50 



MKMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[vol. 10 



Classification of the species of Clusia has been historically, and is for the most 

 part herein, based predominantly on the highly diversified androecium of the 

 staminate flower. Of equal fundamental significance is the morphology of the 

 gynoecium, which often, as indeed is true with the members of the Clusiastrum, 

 may more readily indicate close interrelationship than the character and arrange- 

 ment of the stamens. Numbers and arrangement of perianth parts often are 

 of more value for diagnosis of subgeneric taxa than has «enerally been accorded. 



The following- review strives to employ the consideration of basic morphologi- 

 cal organization of flowers of both sexes, and of course concommitant foliar and 

 latex-color character'. 



Sepals 6-14, the upper imbricate; petals 6-8; stamens numerous, the filaments 

 slender, free, the anthers unit icons, more or less equaling the filaments, the con- 

 nective narrow, the thecae clavate or subclavate, dehiscing laterally by a pseudo- 

 pore immediately below the apex, which sometimes extends nearly halfway the 

 length of the anther; rudimentary pistil lacking- in the staminate flower; stami- 

 nodia of the pistillate flower numerous, free, linear, anantherous; ovary 10-16- 

 locular, multiovulate, the ovules biseriate; styles equaling the locules in number, 

 free, terete, slender, radiate; stigmas distally and ventrally affixed; leaves cori- 

 aceous, sessile or subsessile by virtue of a winged petiole; small or large trees, 

 not epiphytic; latex white. 



Confined to tin 1 Guayana Highland of southern Venezuela, adjacent Brazil 

 and British Guiana, and coastal Guiana. 



Key to the Species of Clusia sect. Clusiastrum 



1. Styles filiform, essentially free to the base, exceeding 1 mm in Length, radiate or re- 

 curved; fruit oblong to globose, considerably more than 1 cm thick; anthers linear 

 clavate, commonly exceeding 1 mm in length, dehiscing by subapical lateral pores. 

 Subseet. Crassifolia. 

 2. Leaves obtuse. 



3. Inflorescence 1-3 -flowered, the pistillate usually 1 flowered, the staminate com- 

 monly 3-flowered, when 3-flowered not compact. 

 4. Flower buds (both sexes) massive, 2-3 cm in diameter; petals 5-6 cm long. 

 5. Petals broadly obovate; leaves broadly obovate, 8-18 cm long, 6-10 cm 



broad, thickly coriaceous. 1. C. orassifolia. 



5. Petals oblanceolate; leaves elliptic or elliptic-oblanceolate, 6-14 cm long, 



3-5 cm broad, thinly coriaceous. 2. C. phelpsiana. 



4. FJpwer buds 1.0-1.5 (2.0) em in diameter. 



6. Leaves commonly exceeding 12 cm in length. 



7. Leaves elliptic, 10-16 cm long, 5-7 cm broad; styles 16. 3. C. fdbulamontana. 



7. Leaves oblanceolate ca. 30 cm long, 6-7 cm broad; styles 10-12. 



4. C. steyermarJcii. 



6. Leaves commonly 10 cm or less long. 



8. Sepals 6-7, concave, orbicular, obovate, broadly scarious-margined ; ovary 



not sulcate; leaves oblanceolate, ovate-cuneate, or cuneate. 5. C. pusilla. 



8. Sepals 9-10, ovate, acutish, somewhat keeled, cucullate; ovary strongly 



10-sukate; leaves oblanceolate. 6. C. auiabili.s. 



3. Inflorescence (3) 5-15-flowered, compact, 



9. Stylar beaks lacking; styles ca. 20, 3 mm long; leaves 10-20 cm long, 5-9 cm 



broad, oblanceolate. 7. C. scliom~burg~kii. 



9. Stylar beak 2-4 mm long; styles 16, 3-5 mm long; leaves 20 40 cm long; 



10-15 cm broad, oblanceolate to obovate. 8. C. stplosa. 



2. Leaves elliptic, acute at both ends, their maximum size 5 cm long, 1.5 cm broad; 



flowers diminutive; inflorescence 1 flowered. 9. C. parvifolia. 



