126 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN | VOL. 10 



2. Moronobea pulchra Ducke, Arch. Jard. Bot. Rio de Janeiro 3 : 313. 1922. 



Type. In campina arenosa ad Ponta Negro prope Urbem Manaos, civitatis 

 Amazonas capitalem, 1. A. Ducke 20-11-1910 florif. n. 11,200 (Rio). I have seen 

 Ducke 13649 (NY, P, G, Rio), and in addition CoelJw 2937 (NY) and Ducke, 

 Manaos, Oct-Nov 1931, s.n. (GH). 



A white or pale large flowered form of small stature. Collected on inundable 

 sites near Manaus, Amazonas, Brazil. It is improbable that this population is 

 specifically distinct from M. coccinea, from which it apparently differs only quan- 

 titatively. More likely the varzea population constitutes an ecological variant. 



3. Moronobea riparia Spruce ex PI. & Tr. Ann. Sci. Nat. IV. 14: 296. 1860. 



M. riparia var. fimbrillata R. E. Schultes, Bot. Mus. Leafl. 17: 15. 1955, type: Puerto 

 Colombia, Rio Guainia, Colombia, Schultes, Baker Sr Cabrera 18206. 



M. riparia var. piraparanensis R. E. Schultes, Bot. Mus. Leafl. 17: 16. 1955, type: 

 Comisaria Vaupes, Rio Piraparana, Cafio Oomoofia, Schultes tir Cabrera 11147 . 



Type. Ad flumina Casiquiari, Vasiva et Pacimoni (Venezuela), Spruce 3550 

 (NY, GH). 



Distribution. A medium sized, white flowered, largely riverine tree of the 

 upper Rio Negro-Rio Guainia drainage of Colombia and Venezuela, viz., the Rios 

 Igana, Vaupes, Atabapo, Pacimoni, etc. A single collection, Wilson-Browne 544 

 (NY), from Iramaipang, Kanuku Mts., British Guiana, alt. 1500 ft., seems ref- 

 erable here. 



The variety fimbrillata was distinguished from typical M. riparia because 

 of fimbrillate and somewhat more greenish petals. Eight of the eleven flowering 

 specimens of M. riparia available to me have fimbrillate petals, however showing 

 considerable variability in prominence of this character. The three other spec- 

 imens showed incipient marginal ornamentation. No geographical pattern is 

 evident. It may, therefore, be properly concluded that seldom, if at all, are the 

 petal margins perfectly smooth. Neither the type of var. fimbrillata nor the two 

 cited paratypes have been available to me. 



The var. piraparanensis is said to be characterized by larger flowers with 

 petals 7 cm long and leaves larger and subacute. A single specimen cited, the 

 type, has not been available to me. Of materials examined, petals normally vary 

 in length from 3 cm to 5 cm. 



4. Moronobea rupicola R. E. Schultes, Bot. Mus. Leafl. 17: 17. 1955 (ex descr.). 



Type. Tree 30-40 feet tall, Cerro Isibukuri, Rio Kananari, Comisaria del 

 Vaupes, Colombia, 4 Aug 1951, Richard E. Schultes & I. Cabrera 13384. (Type 

 said to be at Gray Herb.) . Known only from the type locality. 



The plant so designated by Schultes was related by him to M . ptaritepuiana 

 Steyermark of the Gran Sabana region of Venezuela, but differs in having 



. . abruptly acuminate (instead of apically rounded) leaves which are larger, 

 by having three (instead of five) anthers in each staminal bundle, by its much 

 shorter pedicels and by its. lemon-yellow and basally pink (instead of greenish 

 white and apically pink) petals." 



No specimens of M. rupicola have been available to me. The diagnosis and 

 admirable plate indicate spirally contorted stamens (in the description 3, in the 

 plate 4). Thus, on morphological grounds, for these specimens there may be 

 indicated a stronger relation with M. pulchra and/or M. coccinea, But Schultes 



. 



