54 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[ VOL. 10 



Type: tree 20-25 feet tall, leaves coriaceous; sepals white with reddish mar- 

 gins or reddish throughout; young fruit 3 cm in diam., ovoid-oblong, common 

 along- river, dense forest upper reaches of Rio Tirica between Apacara and 

 Torono-tepui, Chimanta Massif at 1400 m alt., Edo. Bolivar, Venezuela, June 

 24, 1953, Steyermark 75977 (holotype NY, isotype F). 



Known only by the type collection, but said to be common by the collector. 

 This species is strikingly characterized by its large narrowly oblanceolate sessile 

 leaves. 



5. Clusia pusilla Steyermark, Fieldiana Bot. 28: 390. 1952. 



? C. cucullata Klotzsch, nom. nud., in Schomburgk, Fauna unci Flora von Britisch-Guiana 

 2: 1094. 1848. 



Small, usually low, rounded or spreading, densely branched tree, usually 1-4 

 m high; branches terete, sometimes somewhat fleshy, internode 1.5-4.0 (6.0) cm 

 long; petioles 2-5 (8) nun long, conspicuously winged, sometimes the Leaf sessile; 

 blades variable, mostly 5-15 cm long, .3-8 cm broad, oblanceolate to broadly 

 ovate-cuneate or cuneate, coriaceous, the midrib prominent, the lateral veins 

 prominulous and ca. 2.5 mm apart, ascending a1 an angle of 40-60° and collected 

 in a marginal vein 1-3 mm from the narrowly h valine often pigmented involute 

 margins; peduncles 3-6 cm long; cymes 1-flowered or 3 (sometimes 5)-flowered 

 in the male plant, more often 1-flowered in female plant ; bracts ordinarily a 

 single pair, ovate, oblong, or obovate. 4—8 mm long; sepals 6-7, the lower pair 

 decussate, the upper imbricate and hardly exceeding 12 mm in length; petals 

 8, white, oblanceolate, 2-3 cm long. 12-22 mm broad; stamens of the male flower 

 numerous, the anterior 6-8 seriate, disposed on a disc ca. 1 mm high and 1.5 mm 

 broad, the filaments 0.5-2.0 mm long, the anthers ca. 2 mm long, retuse at the 

 apex, the filaments of the apical portion or receptacle subulate, ca. 3 mm long, 

 the theeae 2, each lateral and biloCular, dehiscing by a subapical -median elongate 

 pore that reaches the middle of the anther; staminodia of the female flower 

 numerous, several-ranked, 4.5-5.5 mm long, the anthers reduced in size and 

 probably sterile; ovary ovoid, 8 (lO)-locular, the cells many-ovuled, the ovules 

 2-ranked, horizontally arranged; styles 1-2 mm long, radiate, the stigmas 1.2—1.5 

 mm long, ovate, distally adnate, facing upwards. 



Clusia pusilla is known only from the sandstone formations of Guayana, 

 where it is the most widely occurring species of the section. The 33 collections 

 now available show distinct patterns of differentiation, particularly in leaf-form, 

 which coincide with broad geographical distribution, forming recognizably dis- 

 tinct but discontinuous populations or races in three major regions of Venezuelan 

 Guayana. 



The typical subspecies is confined to the drainage of the Rio Caroni including 

 the Gran Sabana and Cerro Guaiquinima. The two evidently most closely related 

 races, at least those of most similar leaf form, occur in the extreme west where 



Fig. 9. a-f, Clusia steyermarkii* 9 . a, fruiting specimen, X V2I b, calyx, as seen from 

 below, X 1 ; <', nearly mature fruit, X %', d, staminodial disc, X 1M>; e, diagram through 

 Staminodia] disc, X 2 ; f , detail of terminal portion of style showing placement of stigma, 

 lateral view, X 5; drawn from Steyermdrlc 75977. g, Clusia amabilis 9, habit, post flowering 

 specimen, / V.> ; drawn from Maguire $ Maguire 40406. h-j, Clusia amabilis $ . h, male 

 flower, X %; i, anther, ventral view, X 15; j, anther, lateral view, X 15; drawn from Maguiri 

 $ Maguire 403X1. 



