594 
Several specimens from the northwest coast have at the same 
time a 3-parted corolla, cymose flowers and annular seeds. In 
habit they suggest G. aspred/éum, but are really quite distinct from 
any described species. They are here named G. cymosum. 
There is little to be said about the other species treated in this 
paper, viz., G. concinnum, asprellum, asperrimum and ¢triflorum. 
They are as a whole quite constant in their characters, and have 
already been well treated by Dr. Gray in the Synoptical Flora. 
A few words might be said about the relation of these species 
to each other. G. palustre, both on account of its fruit and its in- 
florescence and method of branching, shows an affinity with G. 
asprellum, while the leaves are exactly like those of G. Claytoni. It 
is therefore a transition, as it were, from G. trifidum and G. Claytont 
to G. asprellum and its closer relatives. G.concinnum stands some- 
what alone, its affinity being with G. asprellum. The series then 
progresses through G. asperrimum, with slightly hispid fruits to G. 
triforum with its large broad leaves and long-hirsute carpels, and 
on to G. aparine and its allies. 
Below are given the synonomy, description and range of each 
species and variety discussed in this paper, together with a list of 
the more important specimens studied taken by States. For con- 
venience, a synopsis of the species is also given. 
The writer wishes to express his sincere thanks to Dr. Robin- 
son and Dr. Small, who have kindly loaned him the important col- 
lections of Gaiwm in their charge for use in the preparation of 
this paper. 
Synopsis of the Species discussed. 
A. ENDOSPERM ANNULAR IN CROSS-SECTION; FRUIT GLABROUS. 
a. flowers in terminal clusters of three, or axillary and solitary. 
* Corolla 4-parted, lobes acute ; stem smooth or nearly so. 
Leaves linear, acute, mostly in 4’s; plant large, stem long and weak; branches 2 oF 3 
at each node; flowers axillary and solitary on short recurved pedicels; corolla 
lobes acuminate. Western species, G, arcuatum. 
Leaves lance-linear, obtuse, mostly in 4’s, scabrous on the margin and midrib; plant 
smaller, stem more strict and (except in one variety) mostly erect; branches com- 
monly solitary ; flowers on slender straight pedicels in terminal clusters of three} 
corolla lobes acute. Species of the Great Plains and eastward. G. tinctorium. 
* * Corolla 3-parted, small (114 mm. or less in diam.), lobes obtuse; stem retrorse- 
hispid, or in G. Brandegtd smooth ; branches of the plant commonly in 2’s or 3 "s. 
