38 Contributions from tho (Jniv Iirrlmrium 



o. Dorsal margin of aril suberecl 59. P. consobrina. 



a. Dorsal margin <>f aril not suberect, />. 

 /). ( Sapsule Bpreading-pilosulous on Bides, 53. P. cuspidulata. 

 p. ( 'apsule sparsely incurved- or appressed- 

 puberulous on sides, q, 

 (/. Leaves glaucescenl beneath; wings 



6.5-7 nun. long 45. P. appressipilis. 



</. Leaves not glaucescenl beneath ; wings 



5.5 nun. Long 54. P. microtricha. 



//. Stem-pubescence including longer spreading 

 hairs, r. 



r. Lower sepals 1-1.4 mm. long 51. P. brachysepala. 



r. Lower sepals (1.5) 2-3 mm. long, g. 



8. Spreading hairs of stem rather short, 



very numerous 42. P. amphothrix. 



s. Spreading hairs of stem longer, compara- 

 tively few, t. 

 t. Aril with comparatively large umbo. 



49. P. Albowiana. 

 t. Aril with minute umbo, u. 



u. Dorsal margin of aril descending at 



an angle of about 45 58. P. Hayesii. 



u. Dorsal margin of aril horizontal; 

 aril 1.5 mm. deep; leaves lance- 

 olate 44. P. chiapensis. 



u. Dorsal margin of aril obliquely erec- 

 tish; aril 2.3-3.8 mm. deep; 



leaves broadly ovate 59. P. consobrina. 



i . Wings oblong, oblong-oval, or obovate-oblong, 2-4 times as 

 long as wide, v. 

 v. Stem-pubescence of short appressed or incurved hairs 

 only, w. 

 w. Wings 8-9.5 mm. long, x. 



x. Leaves glabrescent 67. P. Seleri. 



x. Leaves rather densely incurved-puberulous beneath. 66. P. isotricha. 



w. Wings 5.5 mm. long or less 59. P. consobrina. 



v. Stem-pubescence including longer spreading hairs, y. 

 y. Wings very narrowly oblong (1.2-1.8 mm. wide), pu- 

 bescent nearly all over outside with rather long 



spreading hairs 57. P. hebantha. 



y. Wings broader, pubescent merely on costa or also to- 

 ward apex with shorter more or less incurved hairs 

 (longer and more numerous in P. panamensis), z. 

 z. Wings 6.5 mm. long or less, aa. 



aa. Seed glabrous; aril rather closely investing seed, 



with short horizontal dorsal lobe .... 60. P. guatemalensis . 

 aa. Seed pubescent; aril much larger, casque-shaped, 

 with obliquely erectish dorsal lobe, bb. 



bb. Aril finely crenate or subentire 61. P. Durandi. 



bb. Aril more or less dentate-lobulate 59. P. consobrina. 



z. Wings 7-10 mm. long, cc. 



cc. Leaves with numerous long straight spreading 

 hairs on veins beneath, dd. 

 dd. Aril 3 mm. deep, with obliquely erectish dorsal 



lobe (Panama) 65. P. panamensis. 



dd. Aril 2 mm. deep, with nearly horizontal dorsal 



lobe (Vera Cruz) 64. P. biformipilis. 



cc. Leaves with hairs of veins beneath nearly all in- 

 curved or appressed, ee. 



ee. Aril strongly lobulate 63. P. costaricensis. 



ee. Aril somewhat 4-angled but subentire 66. P. isotricha. 



