1958] 



THE BOTANY OF THE QUAY AN A HIGHLAND PART III 



129 



The leaves of G. schomburgkiana var. megaphylla are the largest in the genus 

 as known up to date. The leaves in the type collection appear somewhat paler 

 beneath than those of G. schomburgkiana Woodson var. schomburgkiana; the sec- 

 ondary nerves are not so strongly expressed, the connecting veins are fainter or 

 obscure. Although the calyx is much larger, the corolla is approximately the size 

 of that of the typical variety. 



The typical variety previously was known to us only from the original de- 

 scription of the holotype and a single specimen, G. H. H. Tate 1134, Auyan- 

 Tepui, alt. 1850 m, Venezuela, 1937-1938 (NY). This Ttate plant was errone- 

 ously reported as "G. crassifolia" in Brittonia 3: 190 (1938), and the reference 

 to Auyan-tepui under this species in Fieldiana Bot. 28: 1073 (1957) seems to 

 be a perpetuation of the misidentifieation. Xow eight additional excellent col- 

 lections of typical G. schomburgkiana have been made by the 1951-1952 Maguire, 

 Wurdack and Cowan expeditions to Amazonas and Bolivar in Venezuela (all on 

 Roraima sediments, high sandstone). Because of this rich comparative material 

 that has recently become available ,it is now possible to at least partially evaluate 

 the proposed variety; for fuller understanding, further collections of G. schom- 

 burgkiana var. megaphylla are necessary. 



Himatanthus Willd. 



A. Ducke, with good reason, challenges the segregation of this genus from 

 Plumeria L. (Anais Acad. Bras. Ci. 27: 384. 1955). Recent material presents 

 two very anomalous collections of Himatanthus attenuata which will be dis- 

 cussed -below. 



Himatanthus attenuata (Benth.) Woods. 



VENEZUELA: Amazonas: Maguire, Cowan <r Wurdack 30764- A, Cerro Yapaeana, Rio 

 Orinoco, cano north of Cerro Yapaeana to Rio Orinoco, Jan 6, 1951, tree 10 m tall, flowers 

 Avhite. Maguire, Cowan 4' Wurdack 30499, Cerro Yapaeana, Rio Orinoco, occasional, savanna 

 Xo. 1, Dec 31, 1950, shrub to 2 in. Mowers whitish. Maguire 4- Wurdack 34495, Alto Rio 

 Orinoco, frequent in scrub near Yapaeana cano laguna, northwest base of Cerro Yapaeana, elev. 

 150 m, March 16, 1953, shrub 1.5-4 m, flowers white, fragrant. Maguire, Wurdack $• Bunting 

 36178, Great Rapids of the Orinoco, frequent in open moist area along contact between crystal- 

 line laja and Orinoco gallery forest 1 km east of Hotel Amazonas, Pto. Ayaeucho, 100-120 m 

 elev., Nov 12, 1953, shrubby tree 3-6 m, flowers white, fragrant. COLOMBIA: Maguire, 

 Wurdack Sr Bunting 36281, Rio Atabapo, occasional in savanna 1 km west of Cacagual, 130 m 

 elev., Nov 19, 1953, shrub 1-2 m, flowers white, ' ' Platanote. " 



The first collection cited, 30764 A, is strikingly different from the typical 

 plant. The bracts of the inflorescence are very large, about 3.6 cm long and 2.3 

 cm broad. The corollas are large, about 6.5 cm long (boiled) ; corolla-tube 2.5 

 cm long, the lobes 4 cm long, 1.5 cm wide, the anthers about 1.8 mm long. The 

 leaves are atypically rounded at the apex and they have strong marginal nerves ; 

 petioles 2-4 cm long; blades shining, oblanceolate, gradually and greatly nar- 

 rowed at the base, 12-17 cm long, 5-7 cm wide, the secondary nerves close and 

 rectlinear, netted venation prominent on both sides. The large bracts and the 

 strong marginal nerves of the leaves are like those of H. bract eata (A. DC.) 

 Woods., the prominent venation, texture, and luster of the leaves are of good 

 H. attenuata. 



The Colombian collection, 36281, is not only very different from the typical 

 plant but also provides a striking contrast with 30764-A. The leaves are sessile 

 or subsessile, very rigid, short (3-9.5 cm long), rounded at the apex; inflores- 

 cence crowded, small, the bracts oblong, 1-1.5 cm long, mostly rounded at the 



