14 TEXAS RESEARCH FOUNDATION: CONTRIBUTIONS, VOLUME 5 
13. Leaves twice as long, 9-20 cm. long; flowers 4-5 mm. long at 
anthesis; anthers rarely with a few hairs apically, usually 
ebarbate. 
15. Petioles slender, inconspicuously marginate, up to 2 cm. 
long; leaf margin crenate; flowers racemose-corymbose, 
flowering and fruiting in same raceme in late flowering 
stage; rays of hairs of lower surface of leaf appressed or 
subappressed (Ecuador).......... 14. P. Eggerstana. 
15. Petioles marginate, stout, up to 12 mm. long, usually short; 
leaf margin obscurely crenulate or denticulate, subentire; 
flowers corymbose or subcorymbose; rays of hairs of lower 
surface of leaf erect and spreading. 
16. Sepals orange-punctate, pellucid; anthers ovate, 1- 
1.2 tim. lone (raw)... ss. - 15. P. amazonica. 
16. Sepals black-punctate; anthers lanceolate, 2-2.2 mm. 
long. 
17. Hairs of lower surface of leaf distinctly stipitate, as 
in P. chiapensis; filaments about 1.5 mm. long; 
sepals up to 1.5 mm. long (Guatemala, British 
Honduras, Honduras) ....16. P. belizensis. 
17. Hairs of lower surface of leaf sessile or subsessile; 
filaments about 1 mm. long; sepals 1—1.2 mm. 
long (Costa Rica)........ 17. P. aeruginosa. 
7. Pubescence of branchlets and undersurface of leaves fine, mostly stellate 
and usually closely appressed, sometimes subappressed and rather loose, 
often glabrescent; pubescence usually bizonal on lower surface of leaf 
blades. 
18. Flowers 4-parted, rarely 5-parted; ovary papillose-pubescent apically 
or with only a few short hairs. 
19. Inflorescences small, reduced, up to 5 em. long, essentially glab- 
rous; leaves small, acute, obtusish or acuminate, up to 7 ecm. 
long, 3 cm. wide (Guerrero)............18. P. tetramera. 
19. Inflorescences large, pyramidal, up to 15 cm. long, tomentulose; 
leaves large, rounded-obtuse at apex, up to 13 cm. long, 5 cm. 
wide (Guerrero or Michoacan)......... 19. P. obtusa. 
18. Flowers strictly 5-parted; ovary tomentose, at least apically, or 
glabrous and occasionally with scattered hairs apically. 
20. Ovary tomentose, at least apically, the pubescence dense and 
persistent, sometimes minute, often with intermixed erect 
hairs apically, these simple or stellate (characteristics of pubes- 
cence of pistil difficult to describe, elusive; also see species 
31-44). 
21. Inflorescences with thick fleshy branches, the pedicels 1-2 
mm. long, the shorter ones as thick as long; ovules partly 
biseriate. (Costa Rica)...0. 6.1.4: 20. P. crassiramea. 
21. Inflorescences slender, branches not fleshy, the pedicels 
slender, at least 4 mm. long; ovules uniseriate. 
