l - CNCFlora

Volume 91, Number 4
2004
Croat
Revision of Dieffenbachia
and Prernontane rain forest (P-rf) life zones (Hold- averaging 14 cm long (sheathed 0.48-0.9 the petridge,
1967).
iole length). In contrast, plants from Heredia Prov-
Phenology. Flowering of D. oerstedii occurs ince in Costa Rica are smaller than average with
throughout the year, but with the heaviest flowering blades averaging 13.9 cm long and 5 cm wide (2.9
at the end of the dry season and the first part of times longer than wide).
the rainy season, April to September. Fruit matu- The distribution of Dieffenbachia oerstedii in Panration
is more regularly scattered throughout the ama is apparently disjunct with some collections
year.
known from far western Panama, but the species also
Discussion. This species is characterized by its occurs in the vicinity of E1 Cope and La Mesa in
small stature (generally less than 1 m tall); fre- Cocle Province. The populations in E1 Cope have
quently clustered stems; and sharply C-shaped pet- somewhat smaller leaves (9.5-15 cm long), but differ
ioles that are whitish at the base and sheathed only slightly from those in Costa Rica. The E1 Cope
mostly 1/3_3/4 their length, with the sheath obscurely material is otherwise morphologically identical to
free-ending and inequilateral with at least one side populations of DP oerstedii such as those found at La
usually merely rounded or acute rather than auric- Selva in northern Costa Rica.
ulate. Also characteristic are the moderately thin, The petiole sheath of the Cocle populations is
usually small, + ovate-lanceolate blades, which are merely rounded on one side and acute on the other
generally acute to rounded or truncate basally and (vs. auriculate on one side and rounded on the othmatte
or only weakly glossy adaxially.
er side for typical material of D. oerstedii). In ad-
Dief77enbachia oerstedii is the most widespread dition, the midrib is not faintly striate on both surand
ecologically variable species in Central Amer- faces as is usually the case with typical D. oerstedii.
ica. It is extremely malleable in terms of leaf size, The petiole scars are much more oblique than usual
leaf blade shape, and markings, with different with the internodes longer on one side of the stem
blade coloration types (cf. Fig. 20A, B) all found than on the other (vs. more nearly perpendicular to
within the same population. For example, in pop- the stem with the internodes of equal width on both
ulations at Rio Grande de Taracoles at Carara in sides of the stem for typical D. oerstedii). Despite
Costa Rica (0-200 m), the plants of this species the strong morphological similarities, plants from
are robust. The populations of D. oerstedii at 1400 Cocle Province, Panama, differ markedly in their
m in Braulio Carillo National Park (also Costa Rica) ecological requirements. Cultivated plants, for exhave
small anel delivate leaves. In Costa Rica, the ample, will survive well only in an area of nearly
leaf blades tend to be matte or only weakly glossy 100% humidity. Alternatively, the Costa Rican maon
the upper surface. However, elsewhere in Cen- terial from Heredia does very well in the drier parts
tral America the blades are often more glossy. A of the greenhouse.
collection from E1 Salvador (Selby 77-3()78) has In Mexico, Dieffenbachia oerstedii may be conblades
that are initially rather glossy on the upper fused with D. wendlandii since they have similar
surface and weakly glossy on the lower surface (al- leaf blades. Living material of the latter is easily
beit soon turning only weakly glossy above). Plants separated in having petioles with the free portion
in Panama and Costa Rica have blades 2-11 cm terete or obtusely and weakly sulcate (vs. sharply
wide and acute to rounded at the base, whereas in C-shaped and sulcate in D. oerstedii), the base solid
other parts of Central America from Nicaragua to green, and in having the sheath decurrent at the
Mexico the blades are often 14-18 cm wide with apex with one margin overlapping the other (vs.
subcordate leaf bases.
rolled in from both sides in D. oerstedii, with both
Standley (1937) considered Dieffienbachia leopol- sides visible and often protruded at apex and the
dii (Bull. Catal. 1878) similar to or synonymous with sides inequilaterally rounded to auriculate) Com-
D. oerstedii, but the type specimen indicates that it pared with D. oerstedii, D. wendlandii is typically
was actually collected in Colombia, where D. oerste- a larger plant with longer stems, thicker internodes,
dii does not range. 'The species is actually closer to and larger leaves up to 33 cm long and 9.5-15 cm
D. killipii (see discussion under D. killipii). wide, and with the midrib 1.2-1.4 cm wide (vs. 5-
Collections from Mexico and Belize are larger on 6 mm wide for D. oerstedii). In addition, D. wenaverage
than those in Panama, Costa Rica, and dlandii has the stigma bowl-shaped at anthesis with
Nicaragua, with blades 16.5-35 cm long and 6- a protruded central dome. In contrast, the stigma
16.5 cm wide (averaging 23 x 11 cm). Petioles for of D. oerstedii is cushion-shaped.
the same area range from 8.5 to 30 cm long, about Diegenbachia oerstedii is similar to D. killipii in
as long as the blades to 1.7 times longer than the general blade shape and size as well as in often
blade with the sheath from 7.5 to 21.5 cm long,
having the 66flat-raised" upper midrib, but D. killipii
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