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 species 
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 1: 187. 1910. 
1 Med. Rijks Herb. 19: 49-53. 1913. 
