l - CNCFlora

702
Annals of the
Missouri Botanical Garden
(10)15 to 17 per side, sunken to weakly sunken been made during the late rainy season (Augustabove,
raised below; interprimary veins obscure December).
above, obscurely visible below; minor veins mod- Discussion. This species is related to D. Ionerately
distinct on lower surface. INFLORES- gispatha, which differs in being a much more ro-
CENCES 1 to 2 per axil; peduncle (8.5)10-14 cm bust and taller plant (to 3.5 m), having petioles that
long, flattened laterally, pale green; spathe 13-28 dry green and with a long unsheathed portion, and
cm long, 1.3-1.5 times longer than peduncle, pale pistils that are much larger (to 7 mm diam.), many
to medium green outside (sometimes white at an- fewer in number (only to 26), and widely spaced.
thesis), paler within, unmarked, + oblong, acumi- See that species for additional discussion of the
nate at apex, only weakly constricted midway (con- differences. Though D. crebripistillata usually has
stricted area to 3.2 cm wide when flattened); spathe solid green blades, some plants from Cocle (at La
tube 1.5-3 cm wide when furled, 8-8.5 cm wide Mesa near E1 Valle de Ant6n and along the Conwhen
flattened; spathe blade to 2.0-3.2 cm wide tinental Divide north of Llano Grande) have palewhen
furled; spadix 13-26.5 cm long (averaging 18 maculate leaves. Typically the petiole of Dieffencm
long), the free portion 8.5-11 cm long; pistillate bachia crebripistillata is fully sheathed; however,
portion 6-10(12) cm long, 8-12 mm wide; fertile some plants from the Cerro Jefe region (Croat
staminate portion 5-9 cm long, 6-10 mm diam.; 35915, Croat & Zhu 76644, and Dwyer 9497) or
the mostly sterile intermediate portion (1)1.5-2.5 the Rio Guanche region (D¢Arcy 9678 and Croat
cm long, with some sterile male flowers in the up- 11420) rarely have a significallt free portion of the
per 1/3; pistils (57)80 to 100, scattered, frequently petiole 3-5(7) cm long.
adjacent, up to 5 in a row across the width of the Collections from lowland (:ol6n (Croat 75172,
spadix, never more than 5 mm apart; stigmas pale D'Arcy 9678) are somewhat illtermediate between
orange, densely pul)escent; staminodia white, + ob- D. Iongispatha and the mole tv,nical D. crebripistillong,
ca. 2-3 mnl long, rounded at apex; synandria lata from the highlands of l'tlllama. The petioles
irregularly rounde(l at apex, smooth or weakly dim- are not as fully sheathed, witll the free portion of
pled medially, to 2.6-2.8 mm diam.; pollen exsert- the petiole ranging from 4 to 5 cm long in these
ed in slender c realll-colored threads to 3 mlll long. specimens.
INFRUCTESCEN(LIdS with berries ovoid to sul)el- Most collections from E1 (ol)e in Cocle Province
lipsoid, orange to })right red, 8-11 mm long. have fully sheathed petioles all(l leaf blades proportionately
smaller and nallower, averaging only
Distribution sled habitat. Dieffenbachia crebri- 25 cm long (vs. an average of .-37 cm for all other
pistillata is endemie to central and eastern Panama populations of the species) all(l 2.5 times longer
at (100)250-800(975) m, in Tropical wet forest (T- than wide (vs. an average of 1.9 times longer) with
wf), Preniontane wet forest (P-wf), and Premontane petioles averaging only 11..5 ( lll longer (vs. an avrain
forest (P-li) life zones (Holdridge, 1967) in Co- erage of 16 cm for other po^)ulations). These colcle,
Col6n, Panama, and San Blas Provinces. While lections (Antonio 3039; (vroat 44558, 44682,
the species mostly occurs in a few areas of mod- 49155, 67576; Croat & Zhll 76757; FolsonI 1265,
erately high elevations (including Santa Rita Ridge, 3211, 6218; and Sytsrna & An(lersson 4573) differ
Cerro Bruja, Cerro Jefe, Cerro Campana, and La in having smaller elliptic bla(les. The E1 Cope re-
Mesa), it dips down to as little as 100 m along the gion is well known for having tllany ende-mics, and
Colon Province coast in the area of Rio Guanche these plants may represent differences that may uland
Portobelo. Most of these collections differ in timately prove to be important, but for now are behaving
petioles that dry less orange and have the ing considered as D. crebripistillata. One collection
petiole sheath ending somewhat below the blade, from E1 Cope in Cocle Province (Croat 74861) difnever
overtopping the blades. As mentioned else- fers from the above only in having the petiole free
where under D. nitidipetiolata (and below) these above the sheath for a distance of 4.5 cm.
collections may represent hybrids with either D. ni- Etyrnology. The specific epithet is derived from
tidipetiolata or D. Iongispatha.
"creber" (meaning crowded together) and "pistilla"
Phenology. Dieffenbachia crebripistillata flow- (pistils) and refers to the very closely aggregated
ers principally at the end of the dry season (April) pistils on this species in contrast to the widely sepand
in the early part of the rainy season from May arated pistils of D. Iongispatha with which the speto
July, less commonly during the balance of the cies had long been confused.
dry season (January-March) and in the latter part
of the rainy season (August-October). Fruiting time
is poorly known, but most fruiting collections have
Paratypes. PANAMA. Cocle: N of E1 Valle, Cerro
Gaital, Knapp 5758 (MO); E1 Valle de Anton Region, at
La Mesa, 3.2-6 mi. above E1 Valle, Luteyn & Kennedy