160 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
tube, falling with it; in prefloration they are twisted and in the later 
periods of anthesis both become reflexed and twisted corkscrew-like. 
The cuplike calyx is almost always short and broad. The capsule 
is fusiform and filled with a thick wool derived from the endocarp, 
in which are imbedded numerous seeds, like peas in shape, size, and 
color. The floral bud is ovoid and relatively short and the whole 
flower is also thickset with a more or less spherical outline. The flower 
and fruit structures characteristic of this genus are shown in the ac- 
companying illustrations of B. barrigon (pls. 64-67). 
CHARACTERS OF PACHIRA. 
In Pachira the flower is long and slender and the calyx subtubulose; 
the long petals are laciniate to spatulate and are simply reflexed 
during the anthesis; the staminal tube is 4 to 6 times as long as in 
Bombax and is more or less distinctly 5-branched. The arrangement 
of the stamens seems to differ according to the species, the further 
division of the fascicles being for instance nearly dichotomousin Pachira 
macrocarpa and regularly ramified, with a pectinate arrangement in 
Pachira insignis. The fruit, varying in shape from ovoid, as in 
Pachira aquatica to depressed-globose, as in Pachira mmsignis,is always 
more or less rounded at base and tip and often attains very large 
dimensions. The endocarp is silky-lined or somewhat hairy inside, 
but never woolly, and the seeds, irregularly rounded on account of 
being crowded together, are of about the size of a chestnut. Pachira 
macrocarpa is illustrated in plates 68 and 69; P. aquatica in plates 
70 and 71; P. insignis in plates 72 and 73. 
THE DIFFERENCES SUFFICIENT FOR DISTINCTION. 
There are other characters which may help in distinguishing these 
two genera, but the above, with the aid of the illustrations, are suffi- 
cient for our purpose. The general aspect of tho flowers and the 
presence or absence of wool in the fruit are in fact sufficient to dis- 
tinguish at first sight Bombax from Pachira. Besides this, as far as 
indicated by the Panamanian species, the former bloom when the 
tree is absolutely bare of leaves, while the flowers of the latter aro 
often hidden among the thick foliage, which is always entirely devel- 
oped at the time of anthesis. 
EXPLANATION OF PLATES 64—67.—P], 64, flower and floral buds, forest near Old Panama, Panama, Pittier. 
PI. 65, calyx, style, and stamens of preceding specimen, with section of bud showing arrangement of stamens. 
Pl. 66, fruit and leaves, Hope Gardens, Jamaica. PI. 67, fruit with pericarp removed, showing seed mass. 
Hospital Grounds, Ancon, Canal Zone, Panama, Pittier, All natural size, Pl, 66, from photograph by 
G. N. Collins. 
EXPLANATION OF PLATES 68—73,—PI, 68, androecium of Pachira macrocarpa, Nicoya, Costa Rica, Pittier. 
Pl. 69, section of capsule of same species, showing seeds, Chiapas, Mexico. PI. 70, leaf and androecium of 
P. aquatica, Hope Gardens, Jamaica. Pl. 71, pod of same, Hope Gardens, Jamaica. Pl. 72, flower and 
fascicle of stamens, P. insignis, Caracas, Venezuela, Pittier. Pl. 73, fruit of same individual. Pls. 68 to 72 
natural size; pl. 73, scale 2/3. Pls. 69 to 71 from photographs by G. N. Collins. 
