Studies on the Alocasia clade (Araceae) of Peninsular Malaysia I: Alocasia farisii sp. nov. from limestone in Kelantan

Abstract

Alocasia farisii Zulhazman, Norzielawati & P. C. Boyce is described and illustrated from Karst limestone in Kelantan as the first recorded Peninsular Malaysian species of the hitherto wholly Bornean Alocasia princeps complex, within which A. farisii most closely resembles the southwest Sarawak limestone-obligated Alocasia reversa N. E. Br.

Full text

Studies on the Alocasia clade (Araceae) of Peninsular Malaysia I:
Alocasia farisii sp. nov. from limestone in Kelantan
Zulhazman Hamzah , Norzielawati Salleh and Peter C. Boyce
Z. Hamzah (zulhazman@umk.edu.my), Faculty of Earth Science, Univ. Malaysia Kelantan, Jeli Campus, Jeli, Kelantan, Malaysia. – N. Salleh,
Forest Research Inst. Malaysia (FRIM), Kepong, Selangor, Malaysia. – P. C. Boyce, Systematische Botanik und Mykologie, Dept Biologie I,
Ludwig-Maximilians-Univ. M ü nchen, Germany. PCB also at: Inst. for Tropical Biology and Conservation, Univ. Malaysia Sabah, Kota Kinabalu,
Sabah, Malaysia.
Alocasia farisii Zulhazman, Norzielawati & P. C. Boyce is described and illustrated from Karst limestone in Kelantan as
the fi rst recorded Peninsular Malaysian species of the hitherto wholly Bornean Alocasia princeps complex, within which
A. farisii most closely resembles the southwest Sarawak limestone-obligated Alocasia reversa N. E. Br.
In contrast to traditional classifi cations, the most recent
phylogenetic analyses of Araceae (Cusimano et al. 2011,
Nauheimer et al. 2012a, b) reveal Alocasia G. Don as not
closely related to genera such as Colocasia Schott, but instead
forming a well-supported separate clade with Leucocasia
gigantea (Blume) Schott. Consequently Colocasieae (sensu
Mayo et al. 1997) can no longer be used for the Colocasia -
Alocasia alliance because it lacks phylogenetic support. While
Alocasiinae exists formally (Schott, Synopsis Aroidearum
complectans 1856, p. 43) its rank is inappropriate and in any
case its historical usage is incongruent with the reconstructed
phylogeny.
Alocasia comprises about 100 species, including dimin-
utive to massive pachycaul-arborescent terrestrial or epi-
lithic mesophytes, rather rarely helophytes, distributed
from the subtropical eastern Himalayas throughout sub-
tropical and tropical parts of Asia into the western pacifi c
and eastern Australia. Alocasia is uniquely defi ned by the
presence of waxy glands in the axils of the primary and
occasionally secondary veins on the abaxial surface of the
leaf blade (the exception being Alocasia brisbanensis (F.M.
Bailey) Domin). Additional (but not unique) character-
istics are clear or somewhat milky acrid sap, staminate
fl owers forming synandria, and fruits ripening to orange-
scarlet berries.
Although revised for much of its range (Hay and
Wise 1991, Hay 1998, 1999, Boyce and Sookchaloem
2012) Alocasia remains poorly understood and new
species are regularly being discovered (Hay 1994,
2000, Hay et al. 1997, Yuzammi and Hay 1998, Boyce
2007, Kurniawan and Boyce 2011, Wong and Boyce
2016).
When revising Alocasia for Peninsular Malaysia, Hay
(1998) recognized fi ve species, one of which, viz the
pantropical naturalized A. macrorrhizos (L) G. Don,
was considered doubtfully native.  e other species are
Alocasia inornata Hallier f., A. longiloba Miq. (treated
as an ochlospecies, Cronk 1998), A. perakensis Hemsl.,
and A. puber (Hassk.) Schott. None of these are endemic
to Peninsular Malaysia and although some expressions
of A. longiloba are limestone-associated, none of the
species appears geologically constrained (Mashhor et al.
2012).
Against this background, investigation of the bio-
logically diverse Karst limestone formations of Kelantan
(northeast Peninsular Malaysia) has highlighted a small epi-
lithic species of Alocasia (Fig. 1, 2B), clearly not matching
any of those treated in Hay (1998), nor pertinent to any
species occurring in neighbouring  ailand (Boyce and
Sookchaloem 2012). Plants maintained in cultivation at
University Malaysia Kelantan recently fl owered and revealed
themselves to be an undescribed species morphologically
congruent with the til now wholly Bornean Alocasia princeps
complex (Hay, 1998), in which the Kelantan plants most
closely resemble A. reversa N. E. Br. (Fig. 2A, 3), a species
restricted to limestone in southwest Sarawak, Malaysian
Borneo, but from which they diff er as per the diagnosis
presented below.
© 2017  e Authors. Nordic Journal of Botany © 2017 Nordic Society Oikos
Subject Editor: John Parnell. Editor-in-Chief: Torbj ö rn Tyler. Accepted 23 November 2016
Nordic Journal of Botany 000: 001–005, 2017
doi: 10.1111/njb.01436, ISSN 1756-1051
Early View (EV): 1-EV

Figure 1. Alocasia farisii sp. nov. (A) – (B) plants in habitat, (C) – (D) infl orescence at pistillate anthesis, (E) infl orescence at early staminate
anthesis, (F) spadix at pistillate anthesis, spathe artifi cially removed, (G) detail of pistillate fl ower zone, interstice, and lower part of
staminate fl ower zone, (H) sub-mature infructescence, nearside artifi cially removed.
2-EV

Alocasia farisii Zulhazman, Norzielawati
& P. C. Boyce sp. nov. (Fig. 1, 2B)
A species most similar to the Bornean Alocasia reversa ,
notably by the leaf blades adaxially grey-green and dis-
tinctly dark green about main veins and primary veins,
and by having at least some plants with some or all of the
leaf blades peltate, but diff ering by having staminate fl ower
zone only half enclosed in the lower spathe chamber (vs sta-
minate fl ower zone almost entirely enclosed), by ellipsoid
(vs globose) lower spathe, by the spathe lacking a purple
margin, and by fewer and less well-developed interstice
synandrodes.
Type : Malaysia, Kelantan, Tanah Merah, Jentian Forest
Reserve, ca 05 ° 29 ′ 14.5 ″ N, 102 ° 01 ′ 44.5 ″ E, 6 Jul 2011, Nor-
zielawati S. UMK00190 (holotype: Herbarium, Faculty of
Earth Science, Univ. Malaysia Kelantan).
Eponymy
Alocasia farisii is named for HRH Tengku Mohammad
Faris Petra Ibni Tengku Ismail Petra, now known as Sultan
Mohamad V, the Sultan of the Malaysian State of Kelantan,
in recognition of his great enthusiasm in conserving rare and
endemic species in Kelantan.
Description
Small epilithic, seldom terrestrial, mesophytic herb to ca
55 cm tall but mostly about half this height. Rhizome elon-
gated, erect, later distally decumbent, ca 2.5 cm in diameter.
Leaves several together, irregularly interspersed with semi-
fl eshy, later marcescent brown cataphylls to ca 7 cm long.
Petioles ca 10 – 25 cm long, smooth, pale green, sheathing
in the lower 1/3 – 1/2. Leaf blades thinly leathery; juvenile
blades peltate with posterior lobes united for 60 – 90% of
their length; on adult plants mostly all non-peltate, occa-
sionally mixed peltate and non-peltate in some individu-
als, hastato-sagittate to slightly ovato-sagittate, 4 ⫻ 6 cm to
10 ⫻ 13 cm, glossy dark green along the midrib and primary
veins adaxially, the remainder grey-green. Infl orescences 1 – 2
together, subtended by lanceolate membranous pale green,
later marcescent brown, cataphylls; peduncle ca 7 – 13 cm
long at anthesis, smooth, pale green; spathe ca 7 – 12 cm
long; lower spathe ca 2 cm long, ovoid, creamy to very pale
yellow; limb pale green at the tip, remainder creamy white,
the colour extending into the constriction ventrally, at fi rst
erect, then sharply defl ected, oblong lanceolate, mucronate
for ca 10 mm; spadix somewhat shorter than the spathe;
stipe ca 3 mm, conical, green. Pistillate fl ower zone ca 0.7 cm
long; pistils somewhat loosely packed, fl ask-shaped, facing
obliquely upwards; style slender; stigma 2-lobed, white;
interstice with 2 – 3 rows of pearl-like staminodes, these ca 3
mm in diameter, dull pale cream. Staminate fl ower zone ca
1.5 cm long, 4 mm in diameter, subcylindric, slightly con-
stricted ca 1/3 from the base corresponding to spathe con-
striction; synandria rhombo-hexagonal ca 2.5 mm across,
4 – 6-merous, opening by apical pores; synconnective not
expanded, ivory white; appendix roughly isodiametric with
staminate fl ower zone, ca 2.5 cm long, gradually tapering to
a blunt point, faintly longitudinally brain-like channelled,
dull pale cream. Fruiting spathe broadly ovoid, ca 4 cm long;
berries bright orange.
Distribution and ecology
Alocasia farisii is so far known only from the Karst
limestone areas of Jentian (Tanah Merah, ca 05 ° 29 ′ 14.5 ″ N,
102 ° 01 ′ 44.5 ″ E), Gua Musang, and Gua Ikan – Gua Pagar
(Kuala Krai, ca 05 ° 21 ′ 14.5 ″ N, 102 ° 01 ′ 35.3 ″ E), Kelantan,
northeast Peninsular Malaysia. It grows as a lithophyte in
soil and humus pockets on limestone outcrops and boulders,
rather occasionally as terrestrial, on seasonally dry lightly
forested Karst formations, 80 – 160 m a.s.l.
Biogeographical considerations
 e discovery of Alocasia farisii , a species belonging to an
otherwise Bornean taxon complex, in Peninsular Malaysia,
provides yet more indications of the close biogeographi-
cal relationship that exists for plants in northeast Malay
Peninsular and Borneo, postulated as the “ Riau Pocket ”
phytochore by Corner (1960), and elaborated by Ashton
(2005) and Ahmad Sofi man and Boyce (2010).
Figure 2. Alocasia reversa and A. farisii sp. nov. compared. Alocasia
reversa (A) spadix at pistillate anthesis, spathe artifi cially removed.
Alocasia farisii (B) spadix at pistillate anthesis, spathe artifi cially
removed.
3-EV

Figure 3. Alocasia reversa (A) – (B) plants in habitat. Note that leaf blades in (A) are peltate while those in (B) have basal lobes completely
free, (C) – (D) infl orescence at late pistillate anthesis, (F) spadix at late pistillate anthesis, spathe artifi cially removed.
4-EV

Acknowledgements –  e authors would like to thank the Dept of
Earth Science, Univ. Malaysia Kelantan and the Kelantan State
of Forestry Dept of giving permission to done the survey in
forest reserves and also the Univ. Malaysia Kelantan for fi nancial
funding through the short-term research grant R/SGJP/
A03.00/00279A/001/2009/000021.
References
Ahmad Sofi man, O. and Boyce, P. C. 2010. Studies on Monstereae
(Araceae) of Peninsular Malaysia II: Rhaphidophora latevagi-
nata, newly recorded from west Malaysia. – Gard. Bull. Singap.
62: 1 – 8.
Ashton, P. S. 2005. Lambir ’ s Forest:  e world ’ s most diverse
known tree assemblage? – In: Roubik, D. W. et al. (eds),
Pollination ecology and the rain forest: Sarawak Studies,
Springer, pp. 191 – 216.
Boyce, P. C. 2007. Studies on the Alocasia Schott (Araceae –
Colocasieae) of Borneo: I. Two new species from Sarawak,
Malaysian Borneo. – Gard. Bull. Singap. 58: 141 – 154.
Boyce, P. C. and Sookchaloem, D. 2012. Alocasia. – In: Boyce, P.
C. et al. (eds), Flora of  ailand (Acoraceae and Araceae).
Vol. 11. R. For. Dept, Bangkok, pp. 18 – 30, plates V – XI.
Cronk, Q. C. B. 1998.  e ochlospecies concept. – In: Huxley, C.
R. et al. (eds), Chorology, taxonomy and ecology of the fl oras
of Africa and Madagascar. R. Bot. Gard. Kew, pp. 155 – 170.
Corner, E. J. H. 1960.  e Malayan Flora. – In: Purchon, R. D.
(ed.), Proceedings of the Centenary and Bicentenary Congress
of Biology, pp. 21 – 24.
Cusimano, N. et al. 2011. Relationships within the Araceae:
comparison of morphological patterns with molecular phylog-
enies. – Am. J. Bot. 98: 654 – 668.
Hay, A. 1994. Alocasia simonsiana – a new species of Araceae from
New Guinea. – Blumea 38: 331 – 333.
Hay, A. 1998.  e genus Alocasia (Araceae – Colocasieae) in West
Malesia and Sulawesi. – Gard. Bull. Singap. 50: 221 – 334.
Hay, A. 1999.  e genus Alocasia (Araceae – Colocasieae) in the
Philippines. – Gard. Bull. Singap. 51: 1 – 41.
Hay, A. 2000. Alocasia nebula . – Bot. Mag. 17: 14 – 18, pl. 381.
Hay, A. et al. 1997. Alocasia melo . – Bot. Mag. 14: 82 – 86,
pl. 315.
Hay, A. and Wise, R. 1991.  e genus Alocasia (Araceae) in
Australasia. – Blumea 35: 499 – 545.
Kurniawan, A. and Boyce, P. C. 2011. Studies on the Alocasia
Schott (Araceae – Colocasieae) of Borneo II: Alocasia baginda ,
a new species from East Kalimantan, Indonesian Borneo.
– Acta Phytotax. Geobot. 60: 123 – 126.
Mashhor, M. et al. 2012.  e Araceae of Peninsular Malaysia.
Pulau Pinang: Penerbitan Univ. Sains Malaysia, pp. 146.
Mayo, S. J. et al. 1997.  e genera of Araceae. – R. Bot. Gard.
Kew xi ⫹ 370 pp.
Nauheimer, L. et al. 2012a. Giant taro and its relatives: a phylogeny
of the large genus Alocasia (Araceae) sheds light on Miocene
fl oristic exchange in the Malesian region. – Mol. Phylogenet.
Evol. 63: 43 – 51.
Nauheimer, L. et al. 2012b. Global history of the ancient monocot
family Araceae inferred with models accounting for past
continental positions and previous ranges based on fossils.
– New Phytol. 195: 938 – 950.
Wong, K. M. and Boyce, P. C. 2016. Novitates Bruneienses, 6.
Alocasia azlanii (Araceae), a new species from Brunei. – Acta
Phytotax. Geobot. 67: 185 – 189.
Yuzammi and Hay, A. 1998. Alocasia suhirmaniana (Araceae –
Colocasieae): a spectacular new aroid from Sulawesi, Indonesia.
– Telopea 7: 303 – 306.
5-EV