190 Gleason: Centropogon and Siphocampylus 



three new species of Siphocampylus and one of Centropogon from 

 the collections of Williams. Lauterbach published* a single 

 variety in 1910, and in 1913 Zahlbruckner added three speciesf 

 from the collections of Herzog. 



Not all of these various species and varieties still stand just 

 as they were published, but it is worthy of note that the studies 

 in which they appeared were so exhaustive of the material at 

 hand and subsequent collections have been so scanty that the 

 present paper adds but one new species, although a second, recog- 

 nized by Zahlbruckner and given a manuscript name by him, is 

 here published. It is nevertheless fair to assume that more 

 extended collection in Bolivia will bring to light probably a score 

 or more new species. 



Zahlbruckner's work was based largely on the same material 

 as that used by Britton and Rusby, with additional specimens from 

 certain European herbaria. The types of Britton 's and of Rusby's 

 species, and either the types or isotypes of most of Zahlbruckner's 

 species, are in the collections at the New York Botanical Garden. 



The four cited articles by Britton and Rusby include mere 

 enumerations of the species with detached descriptions of their 

 new species and varieties. Zahlbruckner gives in his monograph 

 somewhat more detailed descriptions of the new species and 

 frequent notes on the supposed affiliation of the others, and pre- 

 faces each genus with a key to the species included. His keys, 

 however, are in general based on minor characters. While 

 obviously related species are in most cases keyed out together, 

 the characters used in distinguishing them are not of fundamental 

 importance, give little idea of the relationship of the species, and 

 can not be successfully used for the species of other South American 

 countries. 



Centropogon and Siphocampylus present the usual lobeliaceous 

 structure. The leaves are almost always alternate, usually ample 

 in size, and with a wide variation in shape, texture, and pubescence. 

 The inflorescence is in a strict sense a terminal raceme, which by 

 shortening of the internodes and suppression of the bracteal leaves 

 becomes a terminal corymbose or subumbellate cluster, or by 



* Buchtien, Contr. Flora Bolivia I: 187. 1910. 

 t Med. Rijks Herb. 19: 49~53- 1913- 



