Averrhoidium dalyi (Sapindaceae): a new species from Western Amazonia

Abstract

The present paper describes and illustrates the new speciesAverrhoidium dalyi and provides a key to the species ofAverrhoidium. The new species is known from lowland, terra firme forest in the Purus River basin, in Acre, Brazil, and from Manu National
Park in Madre de Dios, Peru.
En el presente artículo se describe, discute e ilustra la nueva especieAverrhoidium dalyi coleccionada en la cuenca del Río Purus en el estado de Acre, Brasil y en el Parque Nacional del Manu en el departamento
Madre de Dios, Peru. También en el presente se provee una clave para las especies deAverrhoidium.

Full text

Brittonia, 54(2), 2002, pp. 112–115. ISSUED: 25 July 2002
q
2002, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.
Averrhoidium dalyi (Sapindaceae):
a new species from western Amazonia
P
EDRO
A
CEVEDO
-R
ODR
I
´
GUEZ AND
M
AR
I
´
A
S. F
ERRUCCI
Acevedo-Rodrı´guez, P. (Smithsonian Institution, Department of Systematic Biol-
ogy (Botany), National Museum of Natural History, MRC-166, Washington, DC
20560-0166, U.S.A.; email: acevedo.pedro@nmnh.si.edu) & M. S. Ferrucci (In-
stituto de Bota´nica del Nordeste, C.C. 209, 3400, Corrientes, Argentina; email:
ibone@espacio.com.ar). Averrhoidium dalyi (Sapindaceae): a new species from
western Amazonia. Brittonia 54: 112–115. 2002.—The present paper describes
and illustrates the new species Averrhoidium dalyi and provides a key to the
species of Averrhoidium. The new species is known from lowland, terra firme
forest in the Purus River basin, in Acre, Brazil, and from Manu National Park in
Madre de Dios, Peru.
Key words: Sapindaceae, Averrhoidium, Acre, Brazil, Madre de Dios, Peru.
Acevedo-Rodrı´guez, P. (Smithsonian Institution, Department of Systematic Biol-
ogy (Botany), National Museum of Natural History, MRC-166, Washington, DC
20560-0166, U.S.A.; email: acevedo.pedro@nmnh.si.edu) & M. S. Ferrucci (Ins-
tituto de Bota´nica del Nordeste, C.C. 209, 3400, Corrientes, Argentina; email:
ibone@espacio.com.ar). Averrhoidium dalyi (Sapindaceae): a new species from
western Amazonia. Brittonia 54: 112–115. 2002.—En el presente artı´culo se de-
scribe, discute e ilustra la nueva especie Averrhoidium dalyi coleccionada en la
cuenca del Rı´o Purus en el estado de Acre, Brasil y en el Parque Nacional del
Manu en el departamento Madre de Dios, Peru. Tambie´n en el presente se provee
una clave para las especies de Averrhoidium.
Averrhoidium Baill. is a small genus of
Sapindaceae found in the lowlands of con-
tinental tropical America. It is currently
considered part of the tribe Doratoxyleae,
and is closely related to the West Indian
genera Hypelate P. Browne, Exothea Mac-
fad., and Euchorium Ekm. & Radlk., and to
the African genus Hippobromus Eckl. &
Zeyder. The genus has a disjunct distribu-
tion, with A. spondioides (Standl.) Acev.-
Rodr. & Ferrucci found in Nayarit, Mexico,
and the remaining species in the lowlands
of South America. A similar disjunct pat-
tern (Mexico–lowland South America) has
been documented for other Sapindaceae, in-
cluding members of Serjania Mill. sect.
Platycoccus Radlk., Cardiospermum L.
sect. Carphospermum Radlk., and Talisia
Aubl. subgenera Cotopais (Radlk.) Acev.-
Rodr. and Pitombaria (Radlk.) Acev.-Rodr.
(Acevedo-Rodrı´guez, 1993; Ferrucci &
Acevedo-Rodrı´guez, 1998; Acevedo-Rodrı´-
guez, in press).
Recent botanical exploration for the on-
going Flora of Acre project and examina-
tion by the second author of Sapindaceae
collections deposited at the Field Museum
of Natural History have yielded the discov-
ery of a new species of Averrhoidium
which we describe herein. This new species
brings the total number of known species
in the genus to four.
Averrhoidium dalyi Acev.-Rodr. & Fe-
rrucci, sp. nov. (Fig. 1)
T
YPE
: BRAZIL. Acre: Municı´pio Cruzei-
ro do Sul, Reserva Extrativista do Alto Ju-

2002] 113
ACEVEDO-RODRI
´GUEZ AND FERRUCCI: SAPINDACEAE
F
IG
.1. Averrhoidium dalyi (Daly et al. 7531, US). A. Fruiting branch. B. Detail of leaf rachis showing
indument. C. Fruits showing apical (left) and basal (right) dehiscence. D. Detail of disc showing indument. E.
Seed, lateral view (left) and ventral view (right). F. Embryo, lateral view.

114 [VOL. 54
BRITTONIA
rua´, Rio Jurua´, Seringal Sa˜o Joao, Coloca-
c¸a˜o Tapau´na, moist terra firme forest on ter-
tiary sediments, terrain hilly, dissected by
deep, narrow stream beds, 9
8
12
9
S, 72
8
41
9
W,
19 Mar 1992 (fr), D. C. Daly, L. Ferreira,
J. Ramos, L. Lima & F. Walthier 7531 (
HO
-
LOTYPE
: US;
ISOTYPE
: NY).
Ab omnibus ceteris speciebus foliolis entegris, et
floribus nectariis pubescentibus differt.
Tree 15–25 m tall, trunk to 13 cm dbh,
with low plank buttresses; outer bark black-
ish or dark grayish brown, thin, shed in pa-
pery or thick plates, inner bark tan. Stems
terete, puberulent, glabrescent at maturity,
minutely lenticellate, dull brown. Leaves al-
ternate, pinnately compound; rachis 5–18
cm long, slender, slightly angular, puberu-
lent to glabrous; distal process early decid-
uous leaving a truncate, sericeous base, ca.
0.5 mm long; leaflets 5–10, alternate to op-
posite, elliptic, 3–10.5
3
1.5–4.5 cm, char-
taceous, concolorous, the adaxial surface
glabrous except for the puberulent midvein,
the abaxial surface sparsely puberulent,
more densely so along veins, the venation
brochidodromous, slightly prominent on
both surfaces, especially the midvein, ter-
tiary venation finely reticulate, the margins
slightly undulate, entire or less often distal-
ly serrate, the apex long-acuminate or less
often acuminate or acute-mucronate, the
base obtuse or acute, sometimes slightly
asymmetrical; petiolules slender, 2–5 mm
long, puberulent, adaxially carinate; peti-
oles nearly terete, slightly thickened at base,
2.5–5 cm long. Thyrses 10–16 cm long,
simple, axes puberulent or glabrous, nearly
terete, slightly striate; fruit pedicels 2–4.6
mm long
3
1.2–1.9 mm diam., articulated
at the base. Flowers unknown. Nectary disk
pubescent, with appressed unicellular or-
ange-brown trichomes, persistent at fruit
base. Fruits irregularly dehiscent, opening
from the apex or from the base, asymmet-
rically subglobose, ellipsoid or obovoid,
puberulent to glabrous, red, 1.5–2.3
3
1.5–
1.9 cm, smooth, the pericarp coriaceous, ca.
0.3 mm thick. Seed solitary, pendent, 1.4
3
1.1 cm, the testa thin, coriaceous-fleshy,
white when fresh.
Common name. Aroeira.
Distribution and ecology. A subcanopy
tree known from the state of Acre, Brazil,
and the Department of Madre de Dios,
Peru, from lowland terra firme forest.
Additional specimens examined. BRAZIL. Acre:
Municı´pio Sena Madureira, basin of Rio Purus, Rio
Macaua˜, Colocac¸a˜o Apuı´, terra firme forest on poorly
drained soils, undulating terrain hilly, dissected by nu-
merous streams, 9
8
48
9
S, 69
8
11
9
W, 29 Mar 1994 (fr),
Daly et al. 8064 (NY); Municı´pio Mal Traumaturgo,
Reserva Extrativista do Alto Jurua, foz de Igarape´ Cai-
pora, Faz. Jose´ Rubens, va´rzea forest, 7 May 1993 (fr),
M. Silveira et al. 494 (NY, US).
PERU. Madre de Dios: Provincia Manu, Parque
Nacional del Manu, Rı´o Manu, Cocha Cashu Station,
11
8
50
9
S, 71
8
25
9
W, floodplain forest, 350 m, 25 Apr
1984 (fr), Foster et al. 9820 (F), 27 Mar 1985 (fr),
McFarland 971 (F).
Averrhoidium dalyi differs from all other
species of Averrhoidium by the entire or
seldom distally serrate (vs. serrate) leaflets,
the puberulent (vs. pilose to densely pilose)
leaf rachis, and the pubescent (vs. glabrous)
nectary disk.
The specific epithet honors Dr. Douglas
C. Daly, collector of the type and assiduous
worker in Brazilian Amazonian botany.
Key to the species of Averrhoidium
1. Leaflets entire or seldom distally serrate; leaf rachis puberulent; nectary disk pubescent
------------------
A. dalyi
1. Leaflets serrate, or seldom subentire; leaf rachis pilose to densely pilose; nectary disk glabrous.
2. Leaflets (10–)11–16, dentate-serrate, acuminate-mucronate at apex
--------------------------------
A. paraguaiense
2. Leaflets 8–10(–12), coarsely serrate-dentate or less often subentire, obtuse or less frequently
acute-mucronate at apex.
3. Leaflets abaxially glabrous; fruit pedicels ca. 6 mm long
---------------------------------------------
A. spondioides
3. Leaflets abaxially puberulous, especially along midveins; fruit pedicels 1.5–3 mm long
--------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A. gardnerianum

2002] 115
ACEVEDO-RODRI
´GUEZ AND FERRUCCI: SAPINDACEAE
Acknowledgments
We thank Alice Tangerini for preparing
the fine illustration, and Mark T. Strong and
Laurence J. Dorr for reviewing the manu-
script. Financial support for the second au-
thor was provided by a Smithsonian Insti-
tution Short-term Visitor Grant and by a
Field Museum Short-Term Visitor Grant.
Literature Cited
Acevedo-Rodrı´guez, P. 1993. Systematics of Serjania
(Sapindaceae) part. I: a revision of Serjania sect.
Platycoccus. Mem. New York Bot. Gard. 67: 1–93.
———. In press. Melicocceae (Sapindaceae): Talisia
and Melicoccus. Fl. Neotrop. Monogr. 87.
Ferrucci, M. S. & P. Acevedo-Rodrı´guez. 1998. Car-
diospermum cuchujaquense (Sapindaceae), a new
species from Sonora, Mexico. Novon 8: 235–238.