3b4 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
beneath except for some crisped hairs on or near the margin; heads solitary, in the 
axils of leaves, 5mm. long; calyx minute, 0.5 mm. or less long; corolla much longer 
(3.5 mim, long), glabrous, the margins of the lobes reddish; stamens yellowish, num- 
erous, united below into a slender tube + mm. long; anthers minute, reddish; pods 
shortly stipitate, strongly curved, forming a half circle or even more strongly curved, 
10 to 12 mm. broad, about 8 em. long, when green rather turgid, but the valves after 
breaking apart flat, covered with a fine pubescence; seeds black, somewhat flattened, 
circular or somewhat angled, 1 em. broad, attached to the pod by a long funiculus, 
Collected by J. N. Rose on the flat plain west of Tehuacan, Puebla, August 1, 1901 
(no. 5840), 
In the field this species resembled very closely 2. padmer?, but it differs in so many 
details that I feel justified in treating it as L have. 
VICIACEAE. 
SYNOPSIS OF THE SPECIES OF COLOGANIA. 
The genus Cologania is entirely American and is restricted almost 
wholly to Mexico. Four species are found in the United States, but 
they belong to the border country and all probably extend into Mexico. 
About three species are found in Central America, one at least extend- 
ing into Mexico. Three species have been described from South 
America, two of which have been reported from Mexico, although 
perhaps only one really extends so far, 
This genus was established by Kunth in 1823 and was based on the 
two species C. procumbens and C. angustifolia, Bentham and Hooker 
in the Genera Plantarum state that there are four or five species, while 
the Kew Index recognizes thirteen, all but one being assigned to North 
America. A careful study of much Mexican material indicates that 
the number of species is much larger than was supposed. Some 
twenty-six species are here recognized from Mexico alone. 
The genus is a very consistent one, being readily distinguished from 
related genera by its slender tubular calyx. The species are rather 
difficult to distinguish, the best characters being in the habit and foliage 
and in the pubescence of the leaflets and calyx. There are probably 
good characters in the pods, but very few specimens have been col- 
lected in fruit. There is a great display of species in the mountains 
and table-land region of Mexico. The writer has collected twenty-nine 
numbers representing some ten species. 
The four United States species have not been frequently collected, 
although three of them have been in our large herbaria for more than 
fifty years. Two of these were taken for species of Humboldt collected 
by him in the mountains of central Mexico, but a careful study of the 
original descriptions seems to justify their separation. 
The United States species are easily distinguished by the subjoined 
key. 
