125 



A SYNOPSIS OF THE SPECIES OF HELIOCARPUS. 



The genus lleliocarpus lias been variously described as having from 

 1 to 5 species. Ilemsley listed 7 species in the Hiologia, but two of 

 them are without specific name. Bentham & Hooker state that 

 there are 4 species; Durand says tliere are 4 or 1, while Dr. Schumann, 

 who has recently studied this genus for Engler & Prantl and had 

 previously elaborated it for the Flora Brasiliensis accepts but a single 

 species. My own study leads me to think that there are from 15 to 20 

 species. This number includes o' species described here for the first 

 time and 3 recent species described by Dr. Watson, all largely based 

 on material not seen by others. In my enumeration I have recognized 

 all the species heretofore published, although 1 or 2 of them arc 

 uncertain and may properly belong to synonomy. For instance I have 

 seen uo plant which seems to answer quite to II. trwhopodus. I can 

 easily make out all tin 1 Mexican species, but there is still some confu- 

 sion in the Central and South American. The type of the genus is II. 

 americanus, one of the rarest species of all, although much material 

 has been referred to it. I have not attempted to treat this genus 

 exhaustively here but more as suggesting needed study. 



The genus is divided nearly equally into two groups by the presence 

 of a stipe or its approximate or entire absence. 



* St'i2>e present, tlougated and somewhat bristly, 

 +- Leaves not appendaged at hase. 

 ++ Sepals unappendaged at tip. 



1. Heliocarpua americauus L. Sp. PI. 1: 448. 1753. Plate VII. 

 This species was based upon plate 16 of Hortits Cliffartiavm. The only plant which 



I have seen in any of our American herbaria which at all approaches it is A. Fendler's 

 No. 1277 IJ (in Herb. Gray) from Venezuela (1854-5). 



Prof. Schumann states that the species was described from specimens grown from 

 seed sent from Mexico, although Linnaeus' figure and description does not seem to 

 answer any plant which we have seen from that country. Linnaeus says the plant 

 is from the warmer parts of America., but docs not state its habitat more definitely. 

 I have here reproduced from Hortm Cliffortian ax the plate npon which //. American H8 

 is based. 



Explanation of Plate.— Fig. 3, leafy branch: fig. J, frail ; figs. 3, 4. Hower; scale about ■; that of 

 original plate, whore the Hower is natural size. 



2. Heliocarpus popayanensis !I. B. K. Nov. Gen. & Sp. ;">: 341. 1821. H. ameri- 



canns popayanensis Schum. in Mart. Kl. Bras. 12, pt. 3: 142. 1SS(». 

 I have not seen the type of this species, which comes from Popayan, U. S. of 

 Colombia, but Miguel Bang's Bolivia plant (No. 1491) has been distributed under 

 this name and answers the description fairly well. It may be characterized as fol- 

 lows: Leaves large, the lower ones cordate at hase, the smaller ones sometimes 

 rounded at base, dark green and somewhat stellate above, very pale and densely 

 Btellate beneath; inflorescence very much spreading, branching dichotoraously, 

 densely pubescent with both simple and stellate hairs; flowers in dense nodose clus- 

 ters on very short pedicels; sepals 4, 4 nun. long, conspicuous, densely pubescent 

 vriihout, glabrous and nerved within: petals small; stamens 16 (in type "18-22"); 

 ovary stipitate; fruit small, the body about 1 mm. in diameter, the marginal plumose 

 hairs about the same length, the sides with short and slender hairs; stipe short for 

 the section, 4 mm. long. 



