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Following the production of a near-comprehensive generic phylogenetic analysis of African angraecoid orchids, paraphyly of the genus Rhipidoglossum relative to Cribbia, Margelliantha and Rhaesteria was in need of being resolved by integrating morphological observations into this newly available molecular framework. Accordingly, we critically revised the diagnostic traits of each genus by examining about 700 herbarium specimens ascribable to 50 species of Rhipidoglossum and its satellite genera. Cribbia, Margelliantha and Rhaesteria are here lumped with Rhipidoglossum, along with Angraecopsis pusilla and Diaphananthe millarii. The presence of pollinaria with two separate disk-shaped viscidia, a trilobed, non-papillate rostellum with midlobe more prominent than lateral lobes and an undivided lip are diagnostic of this more inclusive concept of Rhipidoglossum. In line with this new taxonomic arrangement, 11 new combinations in Rhipidoglossum are made, and Margelliantha lebelii is moved to Diaphananthe and first reported for Uganda.
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Phytotaxa 349 (3): 247–256
Copyright © 2018 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Mark Chase: 18 Apr. 2018; published: 15 May 2018
A revised concept of Rhipidoglossum (Angraecinae, Orchidaceae)
1Herbarium et Bibliothèque de Botanique africaine, C.P. 265, Université Libre de Bruxelles, Campus de la Plaine, Boulevard du Triom-
phe 1050, Brussels, Belgium; E-mail:
2Plant Ecology and Biogeochemistry, C.P. 244, Université Libre de Bruxelles, Campus de la Plaine, Boulevard du Triomphe, 1050,
Brussels, Belgium
3UMR 7207 CNRS-MNHN-UPMC, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, 57 rue Cuvier, CP 48, FR
75005, Paris, France
4AMAP, IRD, CIRAD, CNRS, INRA, Univ de Montpellier, Montpellier, France
5Missouri Botanical Garden, Africa and Madagascar Department, P.O. Box 299, St. Louis, Missouri 63166-0299, USA
6Plant Systematics and Ecology Laboratory, Higher Teachers’ Training College, University of Yaoundé I, P.O. Box 047, Yaoundé, Cam-
7Botanic Garden Meise, Domein van Bouchout, Nieuwelaan 38, B-1860 Meise, Belgium
Following the production of a near-comprehensive generic phylogenetic analysis of African angraecoid orchids, paraphyly
of the genus Rhipidoglossum relative to Cribbia, Margelliantha and Rhaesteria was in need of being resolved by integrating
morphological observations into this newly available molecular framework. Accordingly, we critically revised the diagnostic
traits of each genus by examining about 700 herbarium specimens ascribable to 50 species of Rhipidoglossum and its satel-
lite genera. Cribbia, Margelliantha and Rhaesteria are here lumped with Rhipidoglossum, along with Angraecopsis pusilla
and Diaphananthe millarii. The presence of pollinaria with two separate disk-shaped viscidia, a trilobed, non-papillate
rostellum with midlobe more prominent than lateral lobes and an undivided lip are diagnostic of this more inclusive concept
of Rhipidoglossum. In line with this new taxonomic arrangement, 11 new combinations in Rhipidoglossum are made, and
Margelliantha lebelii is moved to Diaphananthe and first reported for Uganda.
Abstract (French)
Suite à des analyses phylogénétiques presque exhaustives pour les genres d’orchidées angraecoïdes d’Afrique, la paraphylie
du genre Rhipidoglossum par rapport à Cribbia, Margelliantha et Rhaesteria avait besoin d’être revisée en intégrant des
observations morphologiques dans ce nouveau cadre moléculaire. En conséquence, nous avons procédé à une révision cri-
tique des caractères diagnostiques de chaque genre en examinant environ 700 spécimens d’herbiers appartenant à 50 espèces
de Rhipidoglossum et à ses genres satellites. Cribbia, Margelliantha et Rhaesteria sont à regrouper avec Rhipidoglossum,
ainsi qu’Angraecopsis pusilla et Diaphananthe millarii. La présence de pollinies avec deux viscidies discoïdales séparées,
un rostellum trilobé non papilleux, avec son lobe médian plus proéminent que les lobes latéraux, et un labelle entier, sont
les caractères diagnostiques de ce concept plus inclusif du genre Rhipidoglossum. Conformément à ce nouvel arrangement
taxonomique, 11 nouvelles combinaisons de Rhipidoglossum sont proposées et Margelliantha lebelii est transférée dans
Diaphananthe. Margelliantha lebelii est pour la première fois signalée en Ouganda.
Key words: African orchids, angraecoids, Angraecopsis, Cribbia, Diaphananthe, Epidendroideae, Margelliantha, Mysta-
cidium, orchid taxonomy, Rhaesteria, Sphyrarhynchus, stigmatic callus,Vandeae
Rhipidoglossum Schlechter (1918: 81) is part of the mostly Afro-Malagasy subtribe Angraecinae, which has undergone
a spectacular radiation event in the past five million years (Givnish et al. 2015). Generic boundaries in Angraecinae are
248 Phytotaxa 349 (3) © 2018 Magnolia Press
considered by Chase et al. (2015) as one of the major remaining unresolved issues in Epidendroideae taxonomy and
have thus been the focus of a large project concerning the taxonomy of this large group (Simo-Droissart et al. 2018) of
about 760 species (Pridgeon et al. 2014).
Rhipidoglossum was first revised by Summerhayes (1937), who designated Rhipidoglossum xanthopollinium
(Reichenbach 1885: 382) Schlechter (1918: 81) as type species. As most recently circumscribed (Cribb 2014a),
Rhipidoglossum also includes taxa formerly placed in the defunct genera Sarcorhynchus Schlechter (1918: 104) and
Crossangis Schlechter (1918: 141), comprising 38 accepted species confined to tropical and southern Africa (Govaerts
et al. 2017). Based on an overall morphological similarity, Summerhayes (1960) subsumed Rhipidoglossum under
Diaphananthe Schlechter (1915: 53) as a section of the later, and this treatment was subsequently adopted by several
authors working on the flora of Tropical Africa (e.g. Hall 1974, Rasmussen 1974, Cribb 1989, Geerinck 1992, la Croix &
Cribb 1998). However, an enlarged concept of Diaphananthe including Rhipidoglossum was shown to be polyphyletic
by the molecular studies in Carlsward et al. (2006) and Freudenstein & Chase (2015) and a recently produced broad
phylogenetic analysis of Angraecinae (Simo-Droissart et al. 2018), in which Rhipidoglossum is retrieved as sister to
Mystacidium Lindley (1837: 205), Angraecopsis Kränzlin (1900: 171) and Sphyrarhynchus Mansfeld (1935: 706). This
finding has given credit to the taxonomic treatment of Garay (1972), who was the first to reinstate Rhipidoglossum,
drawing attention to the distinctive morphology of the pollinaria with two separate viscidia versus a single viscidium
found in Diaphananthe. Molecular phylogenetics has also shown that Rhaesteria Summerhayes (1966: 191), Cribbia
Senghas (1985: 19), part of Margelliantha Cribb (1979: 329) and Angraecopsis pusilla Summerhayes (1951: 258) are
nested in Rhipidoglossum (Simo-Droissart et al. 2018). Also, Margelliantha caffra (Bolus 1893: t. 8) Cribb & Stewart
(1985: 413) and Diaphananthe millarii (Bolus 1905: 147) Linder (1989: 318), were found to be sister to Rhipidoglossum
plus the satellite genera, Cribbia, Margelliantha and Rhaesteria (Simo-Droissart et al. 2018). Accordingly, Simo-
Droissart et al. (2018) suggested that all these taxa should be lumped into a broad concept of Rhipidoglossum. Here we
critically review the morphological traits that support the taxonomic rearrangements proposed by Simo-Droissart et al.
(2018). A short account of the nomenclatural history is provided for each genus or group of species to be moved into
Rhipidoglossum, and the necessary nomenclatural changes, consisting of 11 new combinations in Rhipidoglossum, are
also presented.
Materials and methods
About 700 specimens of 48 species of Rhipidoglossum, Rhaesteria, Cribbia, Margelliantha, Angraecopsis pusilla
and Diaphananthe millarii, were examined using standard herbarium practices (de Vogel 1987), including material
housed in BM, BR, BRLU, COI, K, LISC, LISU, MO, NU, P and UPS (acronyms following Thiers 2017, continuously
updated). Additionally, the type specimens of Diaphananthe millarii and Margelliantha caffra were not available in
these herbaria and were examined through the Global Plants facility (JSTOR 2000-2017). Photographs of living plants,
retrieved from Orchidaceae of Central Africa (Droissart et al. 2017) and from the World orchid iconography (WOI
2015-2017) of the Swiss Orchid Foundation at the Herbarium Jany Renz and the Botanical Institute of the University
of Basel, were also examined. The distribution of character states indicated as diagnostic for each genus in protologues
and other relevant literature were critically reviewed considering a comprehensive phylogenetic analysis of the African
angraecoids presented in Simo-Droissart et al. (2018). Accordingly, generic boundaries were reassessed adopting a
strictly phylogenetic view of Linnaean taxonomy (e.g. Bateman 2009, Chase et al. 2015).
Taxonomic treatment
New generic boundaries and diagnostic traits of Rhipidoglossum
Rhipidoglossum forms a well-supported clade if Rhaesteria, Cribbia, part of Margelliantha (i.e. excluding M. caffra
and M. lebelii Eb.Fisch. & Killmann in Killmann & Fischer 2007: 745), and Angraecopsis pusilla are subsumed under
it. This group of taxa can be recognised morphologically by the shared presence of pollinaria with two separate disk-
shaped viscidia, a trilobed non-papillate rostellum with midlobe more prominent than lateral lobes and an entire lip.
Overall, presence of two separate viscidia in African angraecoids is relatively infrequent and can only be found in
A REVISED CONCEPT OF RHIPIDOGLOSSUM Phytotaxa 349 (3) © 2018 Magnolia Press 249
Dolabrifolia (Pfitzer 1889: 216) Szlachetko & Romowicz (2007: 54) apart from the Sphyrarhynchus-Angraecopsis-
Mystacidium-Rhipidoglossum clade (Simo-Droissart et al. 2018). Two separate viscidia can also be found in Angraecum
claessensi De Wildeman (1916: 184) and A. firthii Summerhayes (1958: 267), but in this case the two viscidia initially
adhere to each other and come away together when removed from the column (Summerhayes 1958).
Margelliantha caffra and Diaphananthe millarii form a clade sister to this more inclusive concept of Rhipidoglossum,
and since they also share the same general floral morphology (e.g. non-papillate rostellum with a prominent midlobe),
they too are here included in Rhipidoglossum. In turn, Sphyrarhynchus, Angraecopsis and Mystacidium together are
sister to this inclusive concept of Rhipidoglossum, and the four genera share the same trilobed rostellar structure. This
observation led Rice (2005) to move Cribbia, Margelliantha and part of Rhipidoglossum into Angraecopsis, creating the
new subgenera Cardiochilos Rice (2005: 19) and Angraecopidoglossum Rice (2005: 21) within the last to encompass
these species. Contrary to what is stated by Cribb (2014a: 433), Rice (2006) did not formally move Rhipidoglossum
into Mystacidium, despite his claim that no clear differences could be found among Rhipidoglossum, Angraecopsis
and Mystacidium. However, Angraecopsis and Mystacidium present a distinctive trilobed lip and a rostellum in which
lateral lobes are longer or subequal in length to the midlobe, which sets them apart from Rhipidoglossum. Additionally,
in the case of Mystacidium, the lateral lobes of the rostellum are covered in conspicuous papillae absent in any other
closely related taxa. In Angraecopsis sect. Coenadenium Summerhayes (1951: 259), in Mystacidium pulchellum
(Kränzlin 1900: 374) Schlechter (1918: 126) and in Sphyrarhynchus, the two visicidia are connate. A taxonomic
revision of Sphyrarhynchus, Angraecopsis and Mystacidium (the ‘SAM clade’) is presented by Martos et al. (2017),
shedding further light on the taxonomy of the SAM alliance and Rhipidoglossum. Martos et al. (2017) have notably
found Mystacidium to be polyphyletic, with Mystacidium tanganyikense Summerhayes (1945: 113) from Tanzania
and the Zambezian region located in Rhipidoglossum and satellite genera. Despite presence of conspicuous papillae
on the rostellum arms that sets the species apart (Martos et al. 2017), the prominent midlobe of the rostellum of M.
tanganyikense together with overall floral morphology also suggest that it is best treated in Rhipidoglossum. Finally,
future revisionary work should focus on exploring the phylogenetic affinities of poorly known species of Rhipidoglossum
(e.g. Rhipidoglossum stellatum (Cribb 1989: 538) Szlachetko & Olszewski 2001: 850, Rhipidoglossum oxycentron
(Cribb 1977: 180) Senghas 1986: 1111) and the SAM clade (i.e. Mystacidium nguruense Cribb 1989: 596 and M.
pulchellum) endemic to East Africa. Considering their overall floral morphology, M. nguruense may be best treated in
Rhipidoglossum, whereas M. pulchellum with its single viscidium and zig-zag inflorescence axis (Schuiteman 1981)
is probably best placed in Sphyrarhynchus. Inclusion of these species in a comprehensive molecular phylogenetic
framework will be key to further clarify relationships of Rhipidoglossum and putatively morphologically similar
Margelliantha caffra and Diaphananthe millarii:—These two species (Fig. 1F) form a well-supported clade
(Simo-Droissart et al. 2018) characterised by short stems, white tepals contrasting with a green column, slender floral
pedicels, an elongate cylindrical lip spur and a peg-like median rostellar lobe. Both species were formerly placed in
Mystacidium (Bolus 1905) and are endemic to eastern South Africa (Govaerts et al. 2017). Rostellar structure and overall
floral morphology of the two species are similar to those of Rhipidoglossum curvatum (Rolfe 1897: 174) Garay (1972:
195) (Fig. 1B), and the white conspicuously pedicellate flowers with a contrasting green anther cap are reminiscent
of those of Margelliantha and Cribbia thomensis la Croix & P.J.Cribb in Cribb & la Croix (1997: 745). The latter
led Cribb & Stewart (1985) to move Mystacidium caffrum (Bolus) Bolus (1905: 145) to Margelliantha. Afterwards
Linder (1989), recognising the clear similarity of Mystacidium millarii Bolus (1905: 147) and Margelliantha caffra,
moved both into Diaphananthe, drawing attention to their rostellar structure and that of Rhipidoglossum montanum
(Piers 1969: 248) Senghas (1986: 1111) (see also Cribb & Stewart 1985), then regarded as part of Diaphananthe.
Carlsward et al. (2006) were the first to retrieve D. millarii as sister to Rhipidoglossum and Cribbia, a relationship
confirmed by Simo-Droissart et al. (2018), who found this species together with M. caffra as sister of Rhipidoglossum.
We preliminarily considered creating a new genus that would be sister to Rhipidoglossum to accommodate these two
species, but their overall floral resemblance to Rhipidoglossum led us to move both into a morphologically diverse
(Fig. 1) and geographically widespread Rhipidoglossum. In this way, we follow the general prescription of avoiding
the recognition of small genera with little grouping information (Bateman 2009). Mystacidium tanganyikense was
found to be nested in the same clade grouping D. millarii and M. caffra by Martos et al. (2018), who pointed out the
presence of a penicillate callus in the mouth of the spur as a feature common to the three species. In habit, with its short
stem and pendent wiry inflorescences, M. tanganyikense presents some similarities to Rhipidoglossum melianthum
(Cribb 1979: 335) Senghas (1986: 1110) from Tanzania. In turn, regarding its floral morphology, M. tanganyikense is
morphologically similar to R. stellatum and Rhipidoglossum tanneri (P.J.Cribb in Cribb & Stewart 1985: 411) Senghas
(1986: 1111), also from Tanzania, with which it shares a similar midlobe of the rostellum with a conspicuous bifid apex.
250 Phytotaxa 349 (3) © 2018 Magnolia Press
Whether these morphological traits of M. tanganyikense and these Rhipidoglossum species are due to common descent
or a result of convergent evolution associated to a common pollinator guild is something to be ascertained in future
phylogenetic studies of Rhipidoglossum. Without a more comprehensive molecular sampling of Rhipidoglossum and
SAM species, notably from East Africa, we prefer not to transfer M. tanganyikense to Rhipidoglossum at this time.
FIGURE 1. An overview of floral diversity in Rhipidoglossum, including species formerly placed in Rhaesteria, Cribbia and Margelliantha.
A. Rhipidoglossum xanthopollinium. B. Rhipidoglossum curvatum. C. Rhipidoglossum densiflorum. D. Rhipidoglossum rutilum.
E. Rhipidoglossum eggelingii. F. Rhipidoglossum millarii. G. Rhipidoglossum leedalii. H. Rhipidoglossum burttii. I. Rhipidoglossum
clavatum. J. Rhipidoglossum thomense. K. Rhipidoglossum brachyceras. L. Rhipidoglossum confusum. M. Rhipidoglossum pendulum. N.
Rhipidoglossum pusillum. Photographs A & K by Vincent Droissart; B by Thomas Couvreur; C, D, J, L & M by Tariq Stévart; E, H & N
by Eberhard Fischer; F by Benny Bytebier; G by Phillip J. Cribb; I by E. Tanner via the World orchid iconography.
Rhaesteria:—Rhaesteria eggelingii Summerhayes (1966: 191; Fig. 1E), the single species of Rhaesteria, was
found to be deeply embedded in Rhipidoglossum (Simo-Droissart et al. 2018). This Albertine Rift endemic is only
A REVISED CONCEPT OF RHIPIDOGLOSSUM Phytotaxa 349 (3) © 2018 Magnolia Press 251
known from the montane forests of Uganda and Rwanda (Fischer et al. 2010, Govaerts et al. 2017). Specimens
attributed to this taxon were misidentified by Geerinck (1988, 1990) as Angraecum humile Summerhayes (1958:
269) and A. pettersonianum Geerinck (1990: 181; Delepierre & Lebel 2001). The morphological uniqueness of the
genus supposedly rests on the presence of a hammer-shaped median rostellar lobe and connation of tepals along their
basal third (Summerhayes 1966). Comparative morphological analysis revealed, however, that an identical hammer-
shaped rostellum can also be found in some species of Rhipidoglossum, notably R. melianthum, R. ochyrae Szlachetko
& Olszewski (2001: 868), R. stellatum and R. tanneri, and the basal tepal connation, although not as evidently, is
also observed in R. adoxum (Rasmussen 1974: 229) Senghas (1986: 1110). Rice (2005) pointed out the similarity of
Rhaesteria to some species of Rhipidoglossum, notably to R. melianthum and R. stellatum, for which he created the
section Malleiform Rice (2005: 20) within Angraecopsis. Molecular results of Simo-Droissart et al. (2018) indicate,
however, a close relationship of Rhaesteria to R. rutilum (Reichenbach 1885: 382) Schlechter (1918: 81), but a more
comprehensive sampling of Rhipidoglossum is needed to clarify infrageneric taxonomy. In any case, all results strongly
support inclusion of Rhaesteria in Rhipidoglossum.
Margelliantha:—The genus as circumscribed by Cribb (2014b) was revealed to be polyphyletic by Simo-Droissart
et al. (2018) with M. lebelii being nested in Diaphananthe, and M. caffra sister to D. millarii, as previously discussed.
We will first discuss the four species of Margelliantha s.s. originally enumerated by Cribb (1979) in his description of
the genus: Margelliantha leedalii Cribb (1979: 333; Fig. 1G), the type species, Margelliantha globularis Cribb (1979:
331), Margelliantha clavata Cribb (1979: 331) and Margelliantha burttii Summerhayes (1937: 82) Cribb (1979: 331).
These four species form a morphologically cohesive group. Margelliantha burtii (Fig. 1H) is nested in Rhipidoglossum
as sister to Cribbia plus Angraecopsis pusilla (see Simo-Droissart et al. 2018). Margelliantha burttii was originally
described by Summerhayes (1934) in Diaphananthe but later transferred to Rhipidoglossum (Summerhayes 1937).
This species differs from the other three Margelliantha in its larger size and occurrence in the Albertine Rift (Govaerts
et al. 2017). Cribb (1979) based the description of Margelliantha on the shared campanulate pearly white flowers,
ecallose lip, thin-textured rostellum and prominent rim on the lower margin of the stigma. However, none of these
character states is mutually exclusive relative to Rhipidoglossum, and Geerinck (1992) was the first to question whether
Margelliantha should instead be included in Rhipidoglossum (then Diaphananthe sect. Rhipidoglossum). A lip callus
can actually be found in M. clavata (Fig. 1I), challenging the original description and delimitation of Margelliantha.
A prominent lower rim on the stigma, which we suggest being termed a stigmatic callus, also occurs in Cribbia (being
particularly conspicuous in C. pendula la Croix & Cribb in P.J.Cribb & la Croix (1997: 747) and in some species of
Rhipidoglossum such as R. candidum (Cribb 1979: 335) Senghas (1986: 1110) and R. tenuicalcar (Summerhayes 1945:
109) Garay (1972: 196). Although the median rostellar lobe of Margelliantha (and Cribbia) has been described as thin-
textured and digitiform and thus different from the peg-like one reported for Rhipidoglossum, intermediate states can
be observed among Rhipidoglossum species, with R. kamerunense (Schlechter 1906: 161) Garay (1972: 195), and
R. mildbraedii (Kränzlin 1909: 342) Garay (1972: 195), illustrating such morphological variation. Rhipidoglossum
mildbraedii, a little known-species endemic to the volcano belt of eastern Democratic Republic of the Congo (Govaerts
et al. 2017), is particularly close to Margelliantha in its overall morphology. Finally, the striking similarity in floral
morphology among Margelliantha, C. thomensis and M. caffra/D. millari is possibly due to convergent evolution
associated with a shared group of pollinators. We therefore propose to lump Margelliantha with Rhipidoglossum.
Finally, the presence of a single viscidium and a thickened inflorescence axis, reminiscent of that of Diaphananthe
divitiflora (Kränzlin 1895: 28) Schlechter (1918: 98), together with molecular data support the inclusion of M. lebelii
in Diaphananthe. Here, we also report the first record of this species for Uganda and propose a new combination in
agreement with this taxonomic treatment.
Cribbia:—All four species of Cribbia (Fig. 1J–M) were found to be nested in Rhipidoglossum with Angraecopsis
pusilla as their sister (Simo-Droissart et al. 2018). Senghas (1985) described Cribbia as including only C. brachyceras
(syn. Rangaeris biglandulosa Summerhayes 1936: 228). It was a segregate of Rangaeris Summerhayes (1936: 227),
and Senghas alluded to its divergent pollinarium structure comprising two viscidia. Later, Senghas (1986) suggested
a close relationship between Cribbia and Rhipidoglossum based on distinctiveness of their two separate viscidia,
an opinion confirmed by Carlsward et al. (2006) in their molecular analysis. Cribb (1996) and Cribb & la Croix
(1997) described three additional species in the genus from the Atlantic side of central Africa, including two endemics
from São Tomé (Stévart & Oliveira 2000). The column of Cribbia is similar to that of Margelliantha, and the same
comparative considerations relative to Rhipidoglossum also apply here. The most distinctive traits of Cribbia are their
narrowly ovate and not orbicular to flabellate sepals, petals and lip that also occur in most species of Rhipidoglossum.
However, Rhipidoglossum microphyllum Summerhayes (1945: 93) and R. montanum also have narrowly ovate tepals,
and the overall floral appearance of the former is reminiscent of that of Cribbia. Molecular data are pending to clarify
whether this species is closely related to Cribbia. The molecular results of Simo-Droissart et al. (2018) identify a clade
252 Phytotaxa 349 (3) © 2018 Magnolia Press
comprising A. pusilla, Cribbia, Margelliantha, Rhipidoglossum arbonnieri (Geerinck in Arbonnier & Geerinck 1993:
256) Fischer et al. (2011: 445) and R. kamerunense. These taxa share the same habit with short stems and possess
conspicuously pedicellate flowers disposed along a distichous inflorescence and a dorso-ventrally flattened median
rostellar lobe. This set of character states is divergent from most species of Rhipidoglossum, which develop long stems
and have short pedicels. However, additional molecular sampling is needed to resolve the infrageneric taxonomy of
our recircumscribed concept of Rhipidoglossum. Meanwhile, considering all evidence, Cribbia is to be subsumed in
Angraecopsis pusilla:—This species (Fig. 1N) was identified as sister to Cribbia by Simo-Droissart et al. (2018),
and consequently it is also embedded in Rhipidoglossum. This dwarf epiphytic species endemic to the Albertine Rift
(Fischer et al. 2010) was described by Summerhayes (1951), who erected the new section Cardiochilos based on its
entire lip to accommodate this “aberrant species” of Angraecopsis. Its ovate lip, two separate viscidia and rostellar
structure corroborate its relationships as highlighted by Martos et al. (2017) and Simo-Droissart et al. (2018), and,
thus, we propose to move this species to Rhipidoglossum. Two other species of Angraecopsis were included in section
Cardiochilos, Angraecopsis lovettii Cribb (1989: 601) and Angraecopsis malawiensis P.J.Cribb in la Croix et al. (1983:
26), by Cribb & la Croix (1998), but to clarify their position relative to A. pusilla a detailed morphological examination
and molecular analysis is needed for Rhipidoglossum and species in the SAM clade.
New combinations in Diaphananthe and Rhipidoglossum
Diaphananthe lebelii (Eb.Fisch. & Killmann) Descourvières & Stévart comb. nov.
Basionym: Margelliantha lebelii Eb.Fisch. & Killmann in Killmann & Fischer (2007: 745). Type:—RWANDA.
Western Province, Nyungwe National Park, km 76.5 Butare–Cyangugu, 19 December 2007, Fischer & Lebel 14123
(holotype: BR!, BR0000006782504)
Additional specimens examined:—UGANDA. sin. loc., 22 December 1960, Burgess in Mason 691 (K!,10296).
Rhipidoglossum Schlechter (1918: 80). Type species (designated by Summerhayes 1937: 80): Rhipidoglossum
xanthopollinium (Rchb.f.) Schlechter (1918: 81).
Margelliantha Cribb (1979: 329). Type species: Margelliantha leedalii Cribb (1979: 333).
Cribbia Senghas (1985: 19). Type species: Cribbia brachyceras (Summerh.) Senghas (1985: 19).
Rhaesteria Summerhayes (1966: 191). Type species: Rhaesteria eggelingii Summerhayes (1966: 191).
Rhipidoglossum brachyceras (Summerh.) Farminhão & Stévart, comb. nov.
Basionym: Aerangis brachyceras Summerhayes (1934: 213). Type:—DEMOCRATIC REPUBLIC OF THE
CONGO. Virunga Mts.: E. of Mt. Namlagira, Kanamaharargi Lavas, January 1931, Burtt 3123 (holotype: K!,
Homotypic synonyms:
Rangaeris brachyceras (Summerh.) Summerhayes (1936: 228).
Cribbia brachyceras (Summerh.) Senghas (1985: 19).
Azadehdelia brachyceras (Summerh.) Braem nom. superfl. (1988: 34).
Angraecopsis brachyceras (Summerh.) Rice (2005: 19).
Heterotypic synonym:
Rangaeris biglandulosa Summerhayes (1936: 228). Type:—GUINEA. Fouta Djallon: Dalaba Plateau, Diaguissa, 1000–
1300 m, October 1907, Chevalier 18782 (holotype P!, MNHN-P-P00388173; isotype P!, MNHN-P-P00388172).
Rhipidoglossum caffrum (Bolus) Farminhão & Stévart, comb. nov.
Basionym: Angraecum caffrum Bolus (1893: t. 8). Type:—SOUTH AFRICA. Pondoland: Emagusheni inter Fort
William and Umtamvuna, 3500 ft, January 1886, Tyson 2841 (lectotype: BOL image!, BOL149998; isolectotype:
Homotypic synonyms:
Mystacidium caffrum (Bolus) Bolus (1905: 145).
Margelliantha caffra (Bolus) Cribb & Stewart (1985: 413).
Diaphananthe caffra (Bolus) Linder (1989: 318).
Angraecopsis caffra (Bolus) Rice (2005: 19), nom inval..
Rhipidoglossum clavatum (P.J.Cribb) Farminhão & Stévart comb. nov.
Basionym: Margelliantha clavata Cribb (1979: 331). Type:—TANZANIA. Lushoto District: W Usambara Mts,
Magamba Forest Reserve, fl. in cult., 6 March 1943, Eggeling in Moreau 400 (holotype K!, K000284750; isotype
A REVISED CONCEPT OF RHIPIDOGLOSSUM Phytotaxa 349 (3) © 2018 Magnolia Press 253
Homotypic synonym:
Angraecopsis clavata (P.J.Cribb) Rice (2005: 21).
Rhipidoglossum confusum (P.J.Cribb) Farminhão & Stévart, comb. nov.
Basionym: Cribbia confusa Cribb (1996: 359). TYPE:—CAMEROON. Mt Cameroon, Mapanja to Mann’s Spring, 6
October 1992, Thomas 9365 (holotype: K!, K000107356; isotype: YA).
Homotypic synonyms:
Angraecopsis confusa (P.J.Cribb) Rice (2005: 19).
Rhipidoglossum eggelingii (Summerh.) Farminhão & Stévart, comb. nov.
Basionym: Rhaesteria eggelingii Summerhayes (1966: 191). Type:—UGANDA. Kigezi: Impenetrable Forest, on
small savanna tree in grassland on outskirts, November 1948, Eggeling 5849 (holotype: K!, K000306602).
Heterotypic synonym:
Angraecum petterssonianum Geerinck (1990: 181). Type:—RWANDA. Nyungwe: 2300 m, 1975, Troupin 15744
(holotype: BR!, BR0000008814753).
Rhipidoglossum globulare (P.J.Cribb) Farminhão & Stévart, comb. nov.
Basionym: Margelliantha globularis Cribb (1979: 331). Type:—TANZANIA. Morogoro District: Uluguru Mts,
1250 m, 25 September 1932, Wallace 172 (holotype: K!, K000354425).
Homotypic synonym:
Angraecopsis globularis (P.J.Cribb) Rice (2005: 21).
Rhipidoglossum leedalii (P.J.Cribb) Farminhão & Stévart, comb. nov.
Basionym: Margelliantha leedalii Cribb (1979: 333). Type:—TANZANIA. Morogoro District: Uluguru Mts, Bondwa,
track up to E ridge of peak, 23 January 1976, Cribb & Grey-Wilson 10380 (holotype: K!, K000284733).
Homotypic synonym:
Angraecopsis leedalii (P.J.Cribb) Rice (2005: 21).
Rhipidoglossum millarii (Bolus) Farminhão & Stévart, comb. nov.
Basionym: Mystacidium millarii Bolus (1905: 147). Type:—SOUTH AFRICA. Natal: near Durban, 8 January 1902,
Millar in Medley-Wood 8437 (holotype: BOL image!, BOL149999).
Homotypic synonyms:
Diaphananthe millarii (Bolus) Linder (1989: 318).
Angraecopsis millarii (Bolus) Rice (2005: 19).
Rhipidoglossum pendulum (la Croix & P.J.Cribb) Farminhão & Stévart, comb. nov. Basionym: Cribbia pendula
la Croix & P.J.Cribb in Cribb & la Croix (1997: 747). Type:—SÃO TOMÉ AND PRÍNCIPE. Pico São Tomé: 28
February 1995, Brune in la Croix ST38A (holotype: K!, K000220048).
Homotypic synonym:
Angraecopsis pendula (la Croix & P.J.Cribb) Rice (2005: 20).
Rhipidoglossum pusillum (Summerh.) Farminhão & Stévart, comb. nov.
Basionym: Angraecopsis pusilla Summerhayes (1951: 258). Type:—DEMOCRATIC REPUBLIC OF THE
CONGO. Parc National Albert: Nyamlagira–Tsambene, 1700 m, 16 January 1945, Germain 3432 (holotype: BR!,
BR0000008809872; isotype: K!, 10664.000).
Rhipidoglossum thomense (la Croix & P.J.Cribb) Farminhão & Stévart, comb. nov.
Basionym: Cribbia thomensis la Croix & P.J.Cribb in Cribb & la Croix (1997: 745). Type:—SÃO TOMÉ AND
PRÍNCIPE. Pico São Tomé: Brune in la Croix ST38 (holotype : K!, K000306404).
Homotypic synonym:
Angraecopsis summerhayesii Rice (2005: 20), published as a nom. nov.
We thank the curators and staff of BM, BR, BRLU, COI, K, LISC, LISU, MO, NU, P and UPS for making their
collections available and kindly allowing us to use the facilities of their institutions. Lab work and herbarium visits were
supported by the U.S. National Science Foundation (1051547, T. Stévart as PI, G. M. Plunkett as Co-PI.). Additionally,
within the framework of the first author’s MSc and ongoing PhD work, funding was obtained from a TROPIMUNDO
Erasmus Mundus Category B scholarship and by a grant of the Fund for Research Training in Industry and Agriculture
(FNRS-FRIA). We are grateful to the American Orchid Society for support of the three last authors’ work in Central
254 Phytotaxa 349 (3) © 2018 Magnolia Press
Africa. We thank Benny Bytebier, Eberhard Fischer, Phillip J. Cribb and Thomas Couvreur for making available their
photos of Rhipidoglossum. Finally, we thank editor Mark W. Chase and two anonymous reviewers for their comments
and corrections, which helped to improve this manuscript substantially.
Arbonnier, M. & Geerinck, D. (1993 ) Contribution à l’étude des Orchidaceae du Burundi (première partie). Belgian Journal of Botany
126: 253–261.
Bateman, R.M. (2009) Evolutionary classification of European orchids: the crucial importance of maximising explicit evidence and
minimising authoritarian speculation. Journal Europäischer Orchideen 41: 243–318.
Bolus, H. (1893) Icones orchidearum Austro-Africanarum extra-tropicarum. Wesley, London, 50 pl.
Bolus, H. (1905) Contributions to the African flora. Transactions of the South African Philosophical Society 16: 135–152.
Carlsward, B.S., Whitten, W.M., Williams, N.H. & Bytebier, B. (2006) Molecular phylogenetics of Vandeae (Orchidaceae) and the
evolution of leaflessness. American Journal of Botany 93: 770–786.
Chase, M.W., Cameron, K.M., Freudenstein, J.V., Pridgeon, A.M., Salazar G., van den Berg, C. & Schuiteman, A. (2015) An updated
classification of Orchidaceae. Botanical Journal of the Linnean Society 177: 151–174.
Cribb, P.J. (1977) New orchids from south Central Africa. Kew Bulletin 32: 137–187.
Cribb, P.J. (1979) New or little known orchids from East Africa. Kew Bulletin 34: 321–340.
Cribb, P.J. & Stewart, J. (1985) Additions to the orchid flora of Tropical Africa. Kew Bulletin 40: 399–419.
Cribb, P.J. (1989) Orchidaceae (part 3). In: Polhill, R.M. (Ed.) Flora of tropical East Africa. Rotterdam, Balkema, pp. 413–652.
Cribb, P.J. (1996) New species and records of Orchidaceae from West Africa. Kew Bulletin 51: 353–363.
Cribb, P.J. & la Croix, I.F. (1997) A synopsis of the genus Cribbia Senghas (Orchidaceae), with two new species from São Tomé. Kew
Bulletin 52: 743–748.
Cribb, P.J. (2014a) Rhipidoglossum. In: Pridgeon, A.M., Cribb, P.J., Chase, M.W. & Rasmussen, F.N. (Eds.) Genera orchidacearum 6,
Epidendroideae (3). Oxford University Press, Oxford, pp. 431–433.
Cribb, P.J. (2014b) Margelliantha. In: Pridgeon, A.M., Cribb, P.J., Chase, M.W. & Rasmussen, F.N. (Eds.) Genera orchidacearum 6,
Epidendroideae (3). Oxford University Press, Oxford, pp. 405–407.
Delepierre, G. & Lebel, J.-P. (2001) Supplément à l’étude des Orchidaceae du Rwanda et des environs (III). Taxonomania 2: 1–9.
de Vogel, E.F. (1987) Manual of herbarium taxonomy: theory and practice. UNESCO Regional Office for Science and Technology for
Southeast Asia, Jakarta, 164 pp.
De Wildeman, É. (1916) Additions à la Flore du Congo. Bulletin du Jardin botanique de l’État à Bruxelles 5: 117−268.
Droissart, V., Simo, M., Sonké, B., Geerinck, D. & Stévart, T. (2017) Orchidaceae of Central Africa. Available from: http://www.orchid- (accessed 13 October 2017)
Fischer, E., Killmann, D., Delepierre, G. & Lebel, J.-P. (2010) The orchids of Rwanda. An illustrated field guide (Koblenz Geographical
Colloquia, Series Biogeographical Monographs 2). Universität Koblenz-Landau, Koblenz, 439 pp.
Fischer, E., Killmann, D., Lebel, J.-P. & Delepierre, G. (2011) Neue Kombinationen in der Gattung Rhipidoglossum - New combination
in the genus Rhipidoglossum. Die Orchidee 62: 445.
Freudenstein, J.V. & Chase, M.W. (2015) Phylogenetic relationships in Epidendroideae (Orchidaceae), one of the great flowering plant
radiations: progressive specialization and diversification. Annals of Botany 115: 665–681.
Garay, L.A. (1972) On the systematics of the monopodial orchids I. Botanical Museum Leaflets, Harvard University 23: 149–212.
Geerinck, D. (1988) Orchidaceae. In: Troupin, G. (Ed.) Flore du Rwanda–Spermatophytes 4. Musée Royal de l’Afrique Centrale, Tervuren,
pp. 505–629.
A REVISED CONCEPT OF RHIPIDOGLOSSUM Phytotaxa 349 (3) © 2018 Magnolia Press 255
Geerinck, D. (1990). Notes taxonomiques sur des Orchidacées d’Afrique centrale X. Bulletin du Jardin botanique national de Belgique/
Bulletin van de Nationale Plantentuin van België 60: 181–190.
Geerinck, D. (1992) Orchidaceae (seconde partie). In: Bamps, P. (Ed.) Flore d’Afrique Centrale (Zaïre–Rwanda–Burundi) spermatophytes.
Jardin Botanique National de Belgique, Leuven, pp. 297–780.
Givnish, T.J., Spalink, D., Ames, M., Lyon, S.P., Hunter, S.J., Zuluaga, A., Iles, W.J.D., Clements, M.A., Arroyo, M.T.K., Leebens-
Mack, J., Endara, L., Kriebel, R., Neubig, K.M., Whitten, W.M., Williams, N.H. & Cameron, K.M. (2015) Orchid phylogenomics
and multiple drivers of their extraordinary diversification. Proceedings of the Royal Society of London: Biological Sciences 282:
Govaerts, R., Bernet, P., Kratochvil, K., Gerlach, G., Carr, G., Alrich, P., Pridgeon, A.M., Pfahl, J., Campacci, M.A., Holland Baptista, D.,
Tigges, H., Shaw, J., Cribb, P.J., George, A., Kreuz, K. & Wood, J. (2017). World checklist of Orchidaceae, Royal Botanic Gardens,
Kew. Available from: (accessed 10 July 2017)
Hall, J.B. (1974) African orchids: XXXIV. Kew Bulletin 29: 427–429.
JSTOR (2000–2017) Global plants. Available from: (accessed 10 July 2017)
Killmann, D. & Fischer, E. (2007) Margelliantha lebelii, eine neue Margelliantha-Art aus dem Nyungwe Nationalpark, Ruanda
Margelliantha lebelii, a new species of Margelliantha from Nyungwe National Park, Rwanda. Die Orchidee 58: 83–90.
Kränzlin, F. (1895) Orchidaceae africanae. II. In: Engler, A. (Ed.) Beiträge zur Flora von Afrika XI. Botanische Jahrbücher fur Systematik,
Pflanzengeschichte und Pflanzengeographie 22: 17–31.
Kränzlin, F. (1900) Orchidaceae africanae. In: Engler, A. (Ed.) Beiträge zur Flora von Afrika XIX. Botanische Jahrbücher für Systematik,
Pflanzengeschichte und Pflanzengeographie 28: 162–179.
Kränzlin, F. (1900) Orchidaceae. In: Engler, A. (Ed.) Beiträge zur Flora von Afrika XX. Botanische Jahrbücher für Systematik,
Pflanzengeschichte und Pflanzengeographie 28: 367–374.
Kränzlin, F. (1909) Orchidaceae. In: Engler, A. (Ed.) Beiträge zur Flora von Afrika XXXV. Botanische Jahrbücher fur Systematik,
Pflanzengeschichte und Pflanzengeographie 43: 330–343.
la Croix, I.F., la Croix, E.A.S., la Croix, T.M., Hutson, J.A. & Johnston-Stewart, N.G.B. (1983) Malaŵi orchids, volume I, epiphytic
orchids. Montfort, Blantyre, 150 pp.
la Croix, I.F. & Cribb, P.J. (1998) Orchidaceae (part 2). In: Pope, G.V. (Ed.) Flora Zambesiaca 11(2). Royal Botanic Gardens, Kew, pp.
Linder, H.P. (1989) Notes on southern African angraecoid orchids. Kew Bulletin 44: 317–319.
Lindley, J. (1837) Notes upon some genera and species of Orchidaceae in the collection formed by Mr. Drédge, at the Cape of Good Hope.
Companion to the Botanical Magazine 2: 200–210.
Mansfeld, R. (1935) Orchidaceae III. In: Mildbraed, J. (Ed.) Neue und seltene Arten aus Ostafrika (Tanganyika-Territ. Mandat) leg. H. J.
Schlieben, X. Notizblatt des Botanischen Gartens und Museums zu Berlin-Dahlem 12: 703–706.
Martos, F., Le Péchon, T., Johnson, S.D. & Bytebier, B. (2017) A reassessment of Angraecopsis, Mystacidium and Sphyrarhynchus
(Orchidaceae: Vandeae) based on molecular and morphological evidence. Botanical Journal of the Linnean Society 186: 1–17.
Piers, F. (1969) Ober die Orchideen Ostafrikas–Angraecum montanum–eine neue Angraecum-Art aus Ostafrika. Die Orchidee 20: 248.
Pfitzer, E.H.H. (1889) Orchidaceae. In: Engler, A. & Prantl, K. (Eds.) Die natürlichen Pflanzenfamilien 3. Engelmann, Leipzig, pp.
Pridgeon, A.M., Cribb, P.J., Chase, M.W. & Rasmussen, F.N. (2014) Genera orchidacearum 6, Epidendroideae (3). Oxford University
Press, Oxford, 544 pp.
Rasmussen, F.N. (1974) Diaphananthe adoxa sp. nov. (Orchidaceae) from southern Ethiopia and the inclusion of Sarcorhynchus in
Diaphananthe. Norwegian Journal of Botany 21: 227–232.
Reichenbach, H.G. (1885) Comoren-Orchideen Herrn Léon Humblot’s. Flora 68: 377–382.
Rice, R. (2005) A preliminary checklist and survey of the subtribe Aerangidinae (Orchidaceae). Oasis The Journal Publishing Department,
Dora Creek, 51 pp.
Rice, R. (2006) Notes on the subtribe Aerangidinae (Orchidaceae). Oasis 3: 13–16.
Schlechter, R. (1906) Orchidaceae africanae IV. In: Engler, A. (Ed.) Beiträge zur Flora von Afrika XXIX. Botanische Jahrbücher fur
Systematik, Pflanzengeschichte und Pflanzengeographie 38: 142–165.
Schlechter, R. (1915) Orchidaceae Stolzianae, ein Beiträge zur Orchideenkunde des Nyassa-Landes. In: Engler, A. (Ed.) Beiträge zur Flora
von Afrika XVII. Botanische Jahrbücher fur Systematik, Pflanzengeschichte und Pflanzengeographie 53: 477–605.
Schlechter, R. (1918) Versuch einer natürlichen Neuordnung der afrikanischen angraekoiden Orchidaceen. Beihefte zum Botanischen
Centralblatt 36: 62–181.
256 Phytotaxa 349 (3) © 2018 Magnolia Press
Schuiteman, A. (1981) Mystacidium pulchéllum (Krzl.) Schltr. syn. Listrostachys pulchella Krzl. Orchideeen 43: 214–217.
Senghas, K. H. (1985) Cribbia und Microterangis, zwei neue Orchideengattungen. Die Orchidee 36: 19–22.
Senghas, K.H. (1986) 15. Tribus: Vandeae. In: Brieger, F.G., Maatsch, R. & Senghas, K.H. (Eds.) Rudolf Schlechter Die Orchideen,
Beschreibung, Kultur und Zuchtung, ed. 3. Parey, Berlin, pp. 973–1130.
Simo-Droissart, M., Plunkett, G. M., Droissart, V., Edwards, M.B., Farminhão, J.N.M., Ječmenica, V., D’haijère, T., Lowry II, P.P., Sonké,
B., Micheneau, C., Carlsward, B.S., Azandi L., Verlynde, S., Hardy, O.J., Martos, F., Bytebier, B., Fischer, E. & Stévart, T. (2018)
New phylogenetic insights toward developing a natural generic classification of African angraecoid orchids (Vandeae, Orchidaceae).
Molecular Phylogenetics and Evolution 126: 241–249.
Summerhayes, V.S. (1934) African orchids: VI. Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew) 1934: 205–214.
Summerhayes, V.S. (1936) African orchids: VIII. Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew) 1936: 221–233.
Summerhayes, V.S. (1937) A review of the genus Rhipidoglossum Schltr. Blumea, supplement 1: 78–86.
Summerhayes, V.S. (1945) African orchids XVI. Botanical Museum Leaflets, Harvard University 12: 89–116.
Summerhayes, V.S. (1951) A revision of the genus Angraecopsis. Botanical Museum Leaflets, Harvard University 14: 240–261.
Summerhayes, V.S. (1958) African orchids: XXVI. Kew Bulletin 13: 257–281.
Summerhayes, V.S. (1960) African orchids: XXVII. Kew Bulletin 14: 126–157.
Summerhayes, V.S. (1966) African orchids: XXX. Kew Bulletin 20: 165–199.
Stévart, T. & Oliveira, F. (2000) Guide des orchidées de São Tomé et Principe: guia dos orchídeas de São Tomé e Príncipe. ECOFAC,
São Tomé, 258 pp.
Szlachetko, D.L. & Olszewski, T.S. (2001) Orchidacées 3. In: Achoundong, G. & Morat, P. (Eds.) Flore du Cameroun 36. Ministère de la
Recherche Scientifique et Technique, Yaoundé, pp. 666–948.
Szlachetko, D.L. & Romowicz, A. (2007) Dolabrifolia, un nouveau genre d’orchidées de l’alliance Angraecum. Richardiana 7: 53−54.
Thiers, B. (2017) Index herbariorum: a global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual
Herbarium, New York. Available from: (accessed 10 July 2017)
WOI (2015–2017) World orchid iconography. Swiss Orchid Foundation at the Herbarium Jany Renz, Botanical Institute, University of
Basel, Basel. Available from: (accessed 24 August 2017)
... and Rhipidoglossum with glistening white flowers and relatively short spurs from the montane forests of East Africa. These species were formerly placed in Margelliantha P.J.Cribb (Farminhão et al. 2018), with which Y. iversenii shares an identical ecology, growing as epiphytes on mossy branches in montane forest. The pollination of the novelties is not yet known, but T. delepierrei is most likely pollinated by more generalist pollinator, as tipulids, small moths or flies, due to the glistening white floral pieces and small spur. ...
Here we describe and illustrate two new species of angraecoid orchids from East Africa, Tridactyle delepierrei and Ypsilopus iversenii, respectively from Albertine Rift (Rwanda and Uganda) and west Usambaras (Tanzania). The first species is closely allied to the three species of Tridactyle sect. Eggelingiae and to Tridactyle nalaensis. The second species is closely related to Y. leedalii from the southern highlands of Tanzania, and the affinities of these two species to other Ypsilopus are discussed. Diagnostic and morphological characteristics of these new species along with identification keys are provided, including those for the species of Tridactyle from East Africa and the Albertine Rift, and for the species of Ypsilopus sect. Ypsilopus. These new species are threatened with extinction based on the categories of the IUCN Red List, with T. delepierrei suggested to be Endangered (EN B1), while Y. iversenii would be Critically Endangered (CR). Our findings highlight the need for further orchidological inventories and taxonomical studies to support evidence-based conservation and management of the remaining montane forests of East Africa.
... The apparent sister relationship between ancistrorhynchoids and dolabrifolioids (clade C2b) requires further investigation. For clade C2c, which unites Rhipidoglossum sensu Farminhão et al. (2018) and the SAM clade sensu Martos et al. (2018), we propose the name Mystacidioides (mystacidioids), referring to the least inclusive clade containing Mystacidium capense (L.f.) Schltr. and Rhipidoglossum xanthopollinium (Rchb.f.) Schltr. ...
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Angraecoid orchids present a remarkable diversity of chromosome numbers, which makes them a highly suitable system for exploring the impact of karyotypic changes on cladogenesis, diversification and morphological differentiation. We compiled an annotated cytotaxonomic checklist for 126 species of Angraecinae, which was utilised to reconstruct chromosomal evolution using a newly-produced, near-comprehensive phylogenetic tree that includes 245 angraecoid taxa. In tandem with this improved phylogenetic framework, using combined Bayesian, maximum likelihood and parsimony approaches on ITS-1 and five plastid markers, we propose a new cladistic nomenclature for the angraecoids, and we estimate a new timeframe for angraecoid radiation based on a secondary calibration, and calculate diversification rates using a Bayesian approach. Coincident divergence dates between clades with identical geographical distributions in the angraecoids and the pantropical orchid genus Bulbophyllum suggest that the same events may have intervened in the dispersal of these two epiphytic groups between Asia, continental Africa, Madagascar and the Neotropics. The major angraecoid lineages probably began to differentiate in the Middle Miocene, and most genera and species emerged respectively around the Late Miocene-Pliocene boundary and the Pleistocene. Ancestral state reconstruction using maximum likelihood estimation revealed an eventful karyotypic history dominated by descending dysploidy. Karyotypic shifts seem to have paralleled cladogenesis in continental tropical Africa, where approximately 90% of the species have descended from at least one inferred transition from n = 17–18 to n = 25 during the Middle Miocene Climatic Transition, followed by some clade-specific descending and ascending dysploidy from the Late Miocene to the Pleistocene. Conversely, detected polyploidy is restricted to a few species lineages mostly originating during the Pleistocene. No increases in net diversification could be related to chromosome number changes, and the apparent net diversification was found to be highest in Madagascar, where karyotypic stasis predominates. Finally, shifts in chromosome number appear to have paralleled the evolution of rostellum structure, leaflessness, and conspicuous changes in floral colour.
... The species was described in 1997 by the English botanists Isobyl F. la Croix and Phillip J. Cribb (Cribb and la Croix 1997), based on two specimens that flowered in cultivation, out of their natural habitat: one in the Royal Botanic Gardens, Kew (United Kingdom), and the second in the Wageningen University (Netherlands). The entire genus Cribbia was recently transferred to the genus Rhipidoglossum after we highlighted their close affinities using new molecular data (Farminhão et al. 2018). Among this group (i.e., the ex-Cribbia), Rhipidoglossum thomense bears a short stem, distichous inflorescences and erect, pure-white flowers with crystalline and diaphanous appearance and a contrasting green anther cap. ...
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In an earlier paper published in Orchids in June 2020, we have shown that the major threats to the orchid habitats in Atlantic Central Africa are shifting agriculture, followed by selective logging and urbanization. Focusing on the methodology we used and explained to assess the risk of extinction of endemic orchids from ACA, we presented habitat threats and discussed IUCN Red List conservation status of seven threatened species. In the present contribution, we will explain (a) how we identified priority areas for conservation and (b) how we have implemented integrated conservation approaches in Central Africa to ensure preservation of the most threatened species.
Rhipidoglossum pareense, a new species, is described from the Pare mountains of NE Tanzania and compared with R. leedalii (P.J.Cribb) Farminhão & Stévart. Its habitat requirements and conservation status are assessed.
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The genus Cyrtorchis is renowned for its conspicuous white, long‐spurred flowers, but also for its challenging problems of species delimitation due to the great morphological resemblance of their flowers. Based on a preliminary visual inspection of 1752 specimens, 27 morphogroups were defined including 6 unpublished taxa. Then, we used a representative sampling of 171 dried and alcohol‐preserved specimens representing 20 morphogroups to perform linear morphometrics through multivariate analyses on 43 morphological characters in order to confirm morphogroups delineation and identify their discriminant characters. Moreover, the monophyly of the two sections and of 21 morphological entities was tested through molecular analyses in order to produce a natural classification of the genus. DNA sequences from 69 Cyrtorchis specimens belonging to 15 published taxa (seven from C. sect. Homocolleticon, eight from C. sect. Cyrtorchis), six putative new Cyrtorchis taxa, as well as four taxa used as outgroups, were produced using one nuclear (nrITS‐1) and five plastid regions (matK, rps16, trnC‐petN intergenic spacer, trnL‐trnF intergenic spacer, ycf1), and were analyzed using maximum likelihood and Bayesian approaches. We used this phylogenetic framework to infer the morphological character‐state evolution of six floral traits and assess their taxonomic value. Morphological analysis revealed two groups corresponding to the published sections. However, while molecular results recovered the monophyly of C. sect. Cyrtorchis, C. sect. Homocolleticon appears paraphyletic. Of the 21 morphologically defined taxa that were included in the molecular analyses, eight, namely C. aschersonii, C. henriquesiana, C. monteiroae, C. praetermissa, C. ringens, and three new taxa were proven monophyletic. The delimitation of the 19 remaining morphologically identified taxa was assessed using morphological approach only. The ancestral state reconstruction provided new insights into character‐state evolution in the genus by inferring the insertion point of the stipites at the rear third of the length of the viscidium as one of the main synapomorphic characters supporting the monophyly of the genus. Furthermore, viscidium structure, stipites shape, and the lateral lobes of the rostellum were found to be important to infer phylogenetic relationships within the genus.
Endocarpic trichomes have been analyzed in fruits of 267 species from 80 genera of the orchid tribe Vandeae, using light and scanning electron microscopy. They have been observed for the first time in 56 genera and confirmed in the rest. The present study describes their microstructure in Vandeae and suggests a standardization for its terminology. Endocarpic trichomes are unicellular, thin, tightly cylindrical, hollow, with an obtuse apex and an expanded foot. The outer surface shows a helicoidal micro-ornamentation, usually covered by waxes. Perforations of the walls have been mainly observed at the outer surface in the foot, and the basal and apical regions. The inner wall is formed by helicoidal thickenings which are responsible for the movement of the endocarpic trichomes. These are present in all the species studied of Vandeae, irrespectively of the life form.
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Two new species of angraecoid orchid from East and South-central Africa are described and illustrated. Rhipidoglossum lucieae is known from the Eastern Arc Mountains of Tanzania (West Usambaras) and has been misidentified as R. pulchellum in previous floristic treatments. Rhipidoglossum philatelicum is reported from the Eastern Highlands of Zimbabwe (Bvumba and Chimanimani Mts) and has been misclassified under R. subsimplex. Distribution maps and the conservation status of these two novelties are provided. Future directions in epiphytic orchid species discovery in eastern tropical Africa are proposed.
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The controversial Bateman–Pridgeon–Chase recircumscription of genera in the dominantly European subtribe Orchidinae (formulated in 1997 and updated in 2003) was generated by applying an explicit set of self-imposed rules to a phylogeny of 186 samples of Orchidinae and Habenariinae analysed for the nuclear ribosomal ITS region. Here, the five prioritised rules that were used to generate that classification are elucidated for the first time, and their implications for circumscribing several genera within Orchidinae are reviewed. During the last decade, many criticisms have been levelled at both molecular phylogenies and the resulting monophyletic classifications. Although some criticisms have some validity, none represents a serious threat to the increasing dominance of statistically assessed monophyly. DNA-based phylogenies clearly provide the strongest basis for orchid classification, particularly at the genus level. The molecular phylogenies provide the best framework for comparing and interpreting additional data-sets that describe morphology, cytology and/or various of aspects of reproductive isolation; it is important that orchidologists continue to collect such intrinsic data. Extrinsic data such as geographical distribution, ecological preference, and pollinator and mycorrhizal specificity are also valuable but they alone are not sufficient to delimit species and higher taxa, nor are speculations regarding which of the many evolutionary mechanisms might have allowed particular taxa to originate. Authors who reject monophyly as the key criterion for classification have not yet proposed a credible alternative approach that links explicit concepts and methodologies and shares the ability of monophyly to allow a wide range of quantitative data to be converted logically and directly into a natural classification. Despite the phylogenetic revolution of the last 30 years, many formal classifications are still being generated that reflect the ‘instincts’ of experienced taxonomists. Such authoritarian classifications are typically hybrids, compiled from portions of various previous classifications; these ad hoc constructs are far more difficult to justify than classifications that result from a single logical and explicit analysis of a particular carefully compiled, robust data matrix. Authoritarian classifications also tend to be geographically restricted (e.g. to Europe), whereas effective classification requires global analysis (i.e. a monographic rather than a floristic approach to taxonomy is necessary). Monophyletic classifications best serve conservationists and the many other users of taxonomic data, who are justly losing patience with a taxonomic community that apparently cannot agree its primary goals or the best means of achieving them.
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Despite significant progress made in recent years toward developing an infrafamilial classification of Orchidaceae, our understanding of relationships among and within tribal and subtribal groups of epidendroid orchids remains incomplete. To reassess generic delimitation among one group of these epidendroids, the African angraecoids, phylogenetic relationships were inferred from DNA sequence data from three regions, ITS, matK, and the trnL-trnF intergenic spacer, obtained from a broadly representative sample of taxa. Parsimony and Bayesian analyses yielded highly resolved trees that are in clear agreement and show significant support for many key clades within subtribe Angraecinae s.l. Angraecoid orchids comprise two well-supported clades: an African/American group and an Indian Ocean group. Molecular results also support many previously proposed relationships among genera, but also reveal some unexpected relationships. The genera Aerangis, Ancistrorhynchus, Bolusiella, Campylocentrum, Cyrtorchis, Dendrophylax, Eurychone, Microcoelia, Nephrangis, Podangis and Solenangis are all shown to be monophyletic, but Angraecopsis, Diaphananthe and Margelliantha are polyphyletic. Diaphananthe forms three well-supported clades, one of which might represent a new genus, and Rhipidoglossum is paraphyletic with respect to Cribbia and Rhaesteria, and also includes taxa currently assigned to Margelliantha. Tridactyle too is paraphyletic as Eggelingia is embedded within it. The large genus Angraecum is confirmed to be polyphyletic and several groups will have to be recognized as separate genera, including sections Dolabrifolia and Hadrangis. The recently segregated genus Pectinariella (previously recognized as A. sect. Pectinaria) is polyphyletic and its Continental African species will have to be removed. Similarly, some of the species recently transferred to Angraecoides that were previously placed in Angraecum sects. Afrangraecum and Conchoglossum will have to be moved and described as a new genus.
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The monophyly of Mystacidium and its relationships with other genera in Orchidaceae subtribe Angraecinae (particularly Angraecopsis) have been unresolved. To address this issue, we amplified one nuclear (ITS) and four plastid (matK, trnL-F, ycf1, trnQ-5′rps16) DNA regions for 33 species of Mystacidium, Angraecopsis, Sphyrarhynchus and allied genera. We also analysed the evolution of morphological characters on the molecular phylogenetic trees. The mainly South African genus Mystacidium is shown to be polyphyletic. Whereas all South African species form a clade, one non-South African species (Mystacidium tanganyikense) is placed with species of Margelliantha and Diaphananthe. Angraecopsis is also polyphyletic; sections Angraecopsis and Coenadenium (including Sphyrarhynchus) form separate branches in a clade that also contains Mystacidium s.s., whereas section Cardiochilus is placed with Cribbia. Morphological synapomorphies, in particular the morphology and hairiness of the rostellum, support the highlighted phylogenetic relationships. To maintain an evolutionarily meaningful classification, we propose a restricted concept of Angraecopsis (= section Angraecopsis) and an expanded concept of Sphyrarhynchus (= S. schliebenii plus part of A. section Coenadenium). Until further analysis with greater sampling is conducted, the phylogenetic relationships of M. tanganyikense and of four species in A. section Cardiochilus remain unclear.
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Orchids are the most diverse family of angiosperms, with over 25 000 species, more than mammals, birds and reptiles combined. Tests of hypotheses to account for such diversity have been stymied by the lack of a fully resolved broad-scale phylogeny. Here, we provide such a phylogeny, based on 75 chloroplast genes for 39 species representing all orchid subfamilies and 16 of 17 tribes, time-calibrated against 17 angiosperm fossils. A supermatrix analysis places an additional 144 species based on three plastid genes. Orchids appear to have arisen roughly 112 million years ago (Mya); the subfamilies Orchidoideae and Epidendroideae diverged from each other at the end of the Cretaceous; and the eight tribes and three previously unplaced subtribes of the upper epidendroids diverged rapidly from each other between 37.9 and 30.8 Mya. Orchids appear to have undergone one significant acceleration of net species diversification in the orchidoids, and two accelerations and one deceleration in the upper epidendroids. Consistent with theory, such accelerations were correlated with the evolution of pollinia, the epiphytic habit, CAM photosynthesis, tropical distribution (especially in extensive cordilleras), and pollination via Lepidoptera or euglossine bees. Deceit pollination appears to have elevated the number of orchid species by one-half but not via acceleration of the rate of net diversification. The highest rate of net species diversification within the orchids (0.382 sp sp(-1) My(-1)) is 6.8 times that at the Asparagales crown. © 2015 The Author(s).
31 new taxa of Orchidaceae from South Central Africa are described, including 3 new genera and 25 new species.