\l K.MOIRS. OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 10 



25. Buds closed, narrowly ovoid, 4^5 mm long, hirsute and completely 

 obscured by pale brown hairs 1-1.5 mm long; panicles 3- or 5-flowered, 

 the peduncle 3-6 mm long, scarcely evident; two lateral flowers, if pres- 

 ent, at the base of the peduncle; midvein convex on both surfaces; 

 British Guiana. 9. C. ovoidca. 



25. Calyx with distinct lobes in bud or, if closed, the buds 1.7-2.5 mm long; 

 peduncle evidently elongated and longer than the flowers, 7-10 mm long 

 or longer; lateral flowers, if present, near the middle of the peduncle; 

 midvein usually impressed above (sometimes merely channeled in C. 

 fasciculata) . 



26. Calyx-lobes distinct in bud, 1-1.8 mm long, the calyx splitting irregu- 

 larly longitudinally in anthesis and the lobes subpersistent ; leaves 

 thick, rigidly coriaceous, the lateral veins scarcely apparent in dried 

 leaves. 



27. Leaves caudate-acuminate; plants densely pubescent with very nu- 

 merous closely appressed bright rusty-brown hairs 0.1-0.2 mm long. 



38. (reduced forms of) M. summa. 

 27. Leaves obtusely pointed; plants heavily velutinous with tangled 



flexuous reddish to white hairs 0.5-1.3 mm long. 19. M. buxifolia. 



26. Calyx calyptrate, closed, the calyptra deciduous; leaves acuminate, 

 thinner, the lateral veins numerous and closely parallel ; plants pubes- 

 cent with pale brown hairs (up to 0.4 mm long) overlying appressed 

 pale matted hairs. 4. C. fasciculata. 



Panicles 5-15 cm long or more, with well-developed lateral branches (or in 

 a few species spicate) and numerous (usually 10-30) flowers. 

 I. Panicles 5-10 cm long (2 cm in C. smUhii) , branched from well below the 

 middle and usually with 1 or 2 supernumerary branches from each node in 

 addition to the principal branch; bracts somewhat persistent, lanceolate to 

 ovate, sometimes keeled, 2-5 mm long ; buds closed, 2.5-4 mm long, obovoid, 

 calyptrate, appressed-pubescent (or velutinous at the base) with reddish- 

 brown hairs to 0.5 mm long ; plants often dioecious. 

 29. Leaves 9-12 cm long; inflorescence (known in bud only) 2 cm long; 



British Guiana. 13. C. smithii. 



29. Leaves (15-) 20-30 cm long or more; inflorescence 5-10 cm long. 

 30. Leaves tapering to a slender apex from the middle or below; inflores- 

 cence 5 cm long or less, few-flowered ; Amazonian Brazil to south- 

 western Venezuela. 7. C. macrophylla. 

 30. Leaves abruptly and narrowly acuminate; inflorescence 6-10 cm long, 



many-flowered; Guianas. 14. C. speciosa. 



3. Spikes (in 1 species) or panicles 4-15 cm long, with open opposite or sub- 

 opposite branching; bracts small, usually deciduous much before anthesis; 

 buds and pubescence various. 

 31. Inflorescence spikelike, the individual spikes 8-10 cm long, 12- to 15- 

 flowered ; buds closed, calyptrate, 4.5-5 mm long, heavily strigose with 

 yellowish- or rusty-brown hairs; Suriname. 15. C. spicata. 



31. Inflorescence paniculate, mostly 2 or 3 times compound. 



32. Pubescence of very numerous minute closely appressed bright rusty 

 brown dibrachiate persistent hairs 0.1-0.2 mm long ; leaves rigidly 

 coriaceous; calyx-lobes free in bud; buds 3.5-5 mm long; Guayana 

 (Venezuela), at elevations of 1400-1900 m. 

 33. Leaves caudate-acuminate, 2.5-5.5 times as long as wide. 



38. M. summa var. sumn>n. 



33. Leaves obtuse or bluntly short-acuminate, 1.7-2.4 times as long as 

 wide. 38. If. summa var. superior. 



32. Pubescence often partly deciduous, variously colored, some or all of the 

 hairs 0.5-1 mm long or more, appressed or spreading; leaves and flow- 

 ers various. 



34. Lateral veins impressed above, 12-20 pairs, readily counted and 

 much stronger than the intermediate veins; leaves rigidly coriaceous, 



