66 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



* 4 



[vol. 10 



7. Leaves 7-22 cm long, acute or acuminate; petiole 3-6 mm long; at least 

 the vegetative buds and young shoots markedly pubescent; branchlets 

 winged or angled. 



8. Branchlets winged, the wings 0.5-3 mm high; leaves merely acute or 

 shortly and obscurely acuminate; petiole 3-4 mm long; Rio Negro 

 (Brazil) to Rio Casiquiare (Venezuela). 17. M. bipennis. 



8. Branchlets obscurely or acutely angled, or subalate, the wing much less 



than 0.5 mm high; leaves narrowly or abruptly acuminate; petiole 5-6 

 mm long; British Guiana to Trinidad and St. Vincent. 25. M. guildingiana. 

 7. Leaves 2.5-6 cm long, obtusely pointed or rounded at the apex; petiole 1-3 

 mm long; pubescence various; branchlets narrowly winged; Guayana. 



9. Plants (except the vegetative buds) completely glabrous; leaves 1.5-2.5 



cm wide, elliptic, 2.3-3 times as long as wide. 28. M. Icaruaiensis. 



9. Young shoots and inflorescence thinly pubescent ; leaves 0.3-1.6 cm wide, 



mostly lanceolate, 4—9 times as long as wide. 31. M. maguin i. 



Branchlets compressed or terete, neither winged nor prominently earinate. 

 10. Relatively glabrous plants with short petioles, small obtuse or bluntly pointed 

 leaves (caudate-acuminate in M. scliomburgMana) and small glabrous flowers 

 [petioles 2-3 (-5) mm long; leaves 3.5-8 (-13) cm long; buds glabrous (or near- 

 ly so in M. salficola), 3-3.5 (-5) mm long]. 

 11. Leaves lanceolate to oblanceolate or narrowly elliptic, 1-2 cm wide, 3-4.5 times 

 as long as wide, acute at the base; panicles 5- to 9-flowered; buds 4 mm long, 

 with an attenuate red-strigose base; British Guiana. 34. M. salticola. 



11. Leaves elliptic to ovate or suborbicular, if acute at the base then 2-2.5 times 

 as long as wide, the flowers usually more numerous and the buds glabrous and 

 3-3.5 mm long. 



12. Leaves prominently acuminate; inflorescence-branches glabrous or essentially 

 so. 



13. Leaves caudate acuminate, the linear tip (1-) 1.5-2.5 cm long, 1-1.5 mm 

 wide; midvein convex above; panicles 5- to 7-flo\vered, the flowers mostly 

 terminal and slender-pedicellate; Guianas. 35. M. schomburgTciana, 



13. Leaves deltoid-acuminate, the acumen mostly less than 1 cm long; panicles 

 many- flowered. 



14. Midvein impressed. 10. C. paniculata. 



14. Midvein convex above. 5. C. flori] < ra. 



12. Leaves rounded, obtuse, or obscurely acuminate at the apex: leaves broadly 

 rounded or cordate at the base or, if acute, the flowers 30 or more in each 

 panicle, the midvein flat or convex above, and the inflorescence often notably 

 pubescent, 



15. Leaves subsessile, broadly rounded and subcordate at the base, 6-13 cm 

 long, 1.5-1.7 times as long as wide; inflorescence spikelike, each spike 9- to 

 12-flowered, the flowers sessile and mostly in one terminal cluster; style 

 10-12 mm. long; buds 4-5 mm long; lower Rio Negro, Brazil. 16. C. spruceana. 

 15. Leaves (2-) 3-8 (-10) cm long, variously shaped; inflorescence paniculate, 

 loosely branched, each panicle 10- to 35-flowered, the flowers solitary or in 

 3 's near the tips; style 3.5-6 mm long; buds 3-3.5 mm long. 

 16. Leaves subsessile, broadly rounded to cordate at the base; petioles 2-3 

 (-4) mm long, 1.5-2.5 mm thick; hypanthium relatively thick and coria- 

 ceous with large persistent lobes, the margin neither thin nor uniformly 

 reflexed ; staminal ring coarsely bristly. 

 17. Buds fleshy, coarsely wrinkled in drying; 3-flowered peduncles rela- 

 tively stout, 1-1.3 mm wide, 4-7 (-12) mm long; calyx calyptrate, the 

 calyptra deciduous, the hypanthium margin becoming irregularly 5- to 

 8-lobulate; Venezuela (Rio Guainia) 37. M. sub orbicularis. 



17. Buds not wrinkled or but obscurely so in drying; 3-flowered peduncles 

 slender, 1 mm wide or (usually) less, (7-) 10-20 mm long; calyx 

 usually not definitely calyptrate but splitting irregularly longitudinally, 

 the 3-4 lobelike segments reflexed and persistent; Guianas. 



32. M. montana. 



