582 COISTTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



III. ADENOPHORA. 

 Leaves obovate. 



Leaves iucurved-pubescont 42. P. glandulosa. 



Leaves nearly glabrous 43. P. phoenicistes. 



Leaves linear to oblong-lanceolate 44. P. macradenia. 



IV. BILOBA. 



Lower sepals glabrous; flowers purple; racemes many-flowered. 

 Bracts deciduous, equaling the pedicels ; stems canescent-pilosulous. 



45. P. purpusii. 

 Bracts persistent, shorter than the pedicels; stems incurved-pubescent but 



green 46. P. conzattii. 



Lower sepals ciliate ; flowers greenish ; racemes 1 to 4-flowered 47. P. parryi. 



V. HUATECA. 



A single species 48. P. tehuacana. 



VI. HEBECLADA. 



Wings densely ciliate; seed pilose-tomentose ; aril large 49. P. floribunda. 



Wings very minutely glandular-ciliolate ; seed pilosulous ; aril minute. 



50. P. apopetala. 

 VII. EURHINOTROPIS. 



Flowers 8.5 mm. long, purplish and yellowish 51. P. fishiae. 



Flowers 4 to 5.5 mm. long, white or rosy. 



Leaves oval, glabrous or sparsely incurved-puberulous. 



Leaves 1 to 2 cm. long, 4 to 12.5 mm. wide 52. P. nitida. 



Leaves 4 to 9 mm. long, 2 to 6.5 mm. wide 53. P. eucosma. 



Leaves squamiform to lanceolate or, when broader, densely pubescent. 

 Leaves not squamiform. 



Leaves, at least the lower ones, oval to suborbicular, like the stem 

 densely spreading or incurved-spreading-pubescent. 



54. P. lindheimeri. 

 Leaves mostly linear to lanceolate, merely incurved-puberulous like the 



stem 55. P. tweedyi. 



Leaves squamiform, 1 to 4.5 mm. long 56. P. ininutifolia. 



VIII. PANTOMONE. 



A single species 57. P. desertorum. 



IX. MOMSTINOPSIS. 



Capsule more than twice as long as wings 58. P. semialata. 



Capsule less than one and one-half times as long as wings. 



Stem glabrous 59. P. hemipterocarpa. 



Stem strigillose or puberulous. 



Wings 5 mm. long 60. P. watsoni. 



Wings 2.5 to 3.5 mm. long. 



Leaves linear or acicular; stem strigillose or incurved-puberulous. 

 Capsule oblong, about twice as long as wide. 



Leaves strongly 2-sulcate beneath 61. P. scoparioides. 



Leaves not 2-sulcate beneath. 



Capsule 2 mm. long; aril 1 mm. long 62. P. dolichocarpa. 



Capsule 2.7 to 3 mm. long; aril 1.5 mm. long 63. P. scoparia. 



Capsule suborbicular or oval, not twice as long as wide. 



64. P. michoacana. 

 Leaves obovate-spatulate ; stems spreading-puberulous 65. P. viridis. 



