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THE BOTANY OF THE GUAYANA HIGHLAND— PART II 



297 



35. Leaf-blades inconspicuously striped if at all, ligulate, 

 conspicuously cretaceous beneath. 

 36. Floral bracts serrulate; sepals strongly nerved, lepidote; 



leaf-blades 20 mm wide.' 20. N. fatifolia. 



36. Floral bracts entire; sepals even, glabrous; leaf-blades 



13 mm wide. 21. N. cretacea. 



32. Leaf-blades not more than 6 mm wide. 



37. Leaf-blades serrulate throughout, glabrous beneath. 22. N. cucullata. 

 37. Leaf-blades with the apical half entire, lepidote beneath at 

 least when young. 

 38. Leaf-sheaths pale brown with broad hyaline margins; floral 



bracts elliptic, obtuse; sepals 12 mm. long. 23. N. wnbratilis. 



38. Leaf-sheaths dark castaneous; floral bracts ovate; acute; 



sepals 8 mm. long. 24. N. semis errata. 



10. Sepals connate posteriorly or equally. 

 39. Sepals 4-6 mm long, acute. 



40. Scape evident, raising the inflorescence above the leaf-sheaths; 



outer bracts short. Colombia: Cerro Chiribiquete. N. bicolor. 



40. Scape short and wholly concealed by the leaf-bases, or none. 



41. Leaf-blades 17 mm wide; plants mostly simple. Colombia: Ama- 



zonas, Vaupes. N. heliophila. 



41. Leaf-blades 2-6 mm wide; plants mostly pulvinate. 



42. Leaf-blades abruptly acute, 6 mm wide. Colombia: Araracoara. 



N. acaulis. 



42. Leaf-blades acuminate, 2-3 mm wide. 



43. Floral bracts much exceeding the sepals; leaf-blades soon 

 deciduous and exposing the branched stem, 3 cm long. Co- 

 lombia: Cerro del Castillo. N. schultesiana. 

 43. Floral bracts shorter than the sepals; leaf-blades persistent 

 and concealing the stem, 7 cm long. Colombia: Chiribi- 

 quete. N. gramini folia, 

 39. Sepals 10-16 mm long. 



44. Leaf-blades serrulate throughout. 



45. Leaf-blades densely cinereous-lepidote beneath, abruptly acute 



or obtuse. 25. N. mima. 



45. Leaf-blades soon glabrous. 



46. Inner leaf-blades white at the base and forming an eye about 

 the inflorescence. 

 47. Leaf-blades 8-10 mm wide; stems mostly branched and plants 



cushion-forming. 26. N. pungens. 



47. Leaf-blades 1-2 mm wide, not narrowed toward the base; 



stems simple. 27. N. ocellata. 



46. Inner leaf-blades concolorous like the others, narrowed toward 

 base; sepals more than half connate. 



48. Leaf-hlades with a conspicuous brown cartilaginous margin, 



densely and distinctly serrulate. 28. N. sandwithii. 



48. Leaf-blades with an inconspicuous almost colorless margin, 

 laxly and obscurely serrulate. Suriname: Tafelberg. 



N. maguirei. 



44. Leaf-blades entire or with a few obscure teeth near the base or the 

 apex. 



49. Sepals obtuse, 16 mm long; leaf-blades 14 mm wide. 



29. N. subpetiolata. 

 49. Sepals acute, 10-12 mm long; leaf-blades 3-5 mm wide. 



50. Leaf-blades spreading, flat, 5 mm wide; floral bracts wholly 



membranaceous. British Guiana, Venezuela. N. gleasonii. 



50. Leaf-blades strict, involute, 3 mm wide; floral bracts subulate- 

 thickened at the apex. 30. N. caricijolia. 

 9. Ovary partly or almost wholly inferior. 

 51. Sepals 28-30 mm long. 



52. Ovary only l / 2 inferior; sepals linear, dilated and denticulate at the 



apex. 31. N. immersa. 



