23 
is without jointing of pod to calyx and with manifest stipe. The 
first group is herbaceous and with nearly prostrate and slender 
stems. A. Howellii has narrow pods, is inclined to be softly pubescent 
and with dirty-white flowers about 1 cm. long, It frequents the 
prairies of the lower Columbia Basin. A, Mulforde has the broad 
and a little inflated pods smooth, and has the small flowers of A. 
campestris, and belongs in the Upper Snake river region on sandy 
slopes. A. Inyoensis is the only annual with long and prostrate 
stems and brilliant purple flowers and broad and obcompressed 
pods as in Mulforde and belongs in the Death Valley region. The 
next group of the Hamosi is marked by the shrubby base, woolly 
pubescence and narrow pods, A. Nevinii has smooth pods and A. 
Traskiæ has woolly pods. Both belong on the islands of southern 
California, . A. Arthuri is a remarkable plant with almost filiform 
and acuminate and elongated pods and the general habit of A, How- 
ellii and belongs in the Lake Waha region of Idaho, 
29. The Leptocarpi seem to branch off from the Hamosi early 
near the first group. The first division contains the species with blunt 
keel, and wings not lobed, and embraces two groups, the first 
containing A. Francisquitensis, Lindheimeri and leptocarpus with 
smooth pods and racemose. The first species belongs in the lower 
California region, and the other two on the Texan prairies, the latter 
species going to central Mexico. The second group has flowers in 
heads, and with two rather distinct segregations. A. tener and 
Rattani belong on the California plains and have pods never shaggy. 
A. Wrightii has shaggy pods and belongs on the Texan prairies. The 
second division of the Leptocarpi embraces the oxytropidoid forms 
with sharp or produced keel and a tendency to lobed wings, and 
wings wide above. A. Nuttallianus has pods arched most near the base 
and rarely inverted on a twisted pedicel, the keel variously sharp, 
and with obovate wings. This is almost everywhere in the Tropi- 
cal life zone and covers most of the Lower Temperate throughout the 
Great Basin. A. acutirostris and nothoxys have acuminate keel and 
pods inverted on a twisted pedicel. The one belongs in the Mo-. 
jave-Death Valley region, the other on the plains or low mountain 
slopes of southern Arizona, and extending into Mexico. The flowers 
of the Leptocarpi are seldom minute. 
30. Micranthi. This is manifestly closely related to the Lepto- 
carpi but with pods inclined to be obcompressed and rather sul- 
cate at both sutures. A. lentiformis is peculiar in the much laterally 
flattened pod like A. tegetarioides, but it is manifestly an ally to 
A. Lemmoni of the same region namely the divide between the 
Great Basin and the Columbia drainage along the Sierras in the 
sagebrush. This group is almost wholly Mexican, with an outlier in 
Texas and three species reaching Arizona and California besides 
those mentioned, Plants with pediceled flowers in racemes are A. 
Madrensis of the pine forests of Chihuahua, the little known A. er- 
voides of Tepic, and Luisianus also of the forests of Oaxaca and Pu- 
ebla. Plants with flowers in loose heads and rather few are the 
mostly woolly A. Greggii of Coahuila and southward. A. Pringlei of 
the Chihuahua plains, A. parvus of the regions of San Luis Potosi, 
and A. Schaffneri from the same region. Plants with flowers in 
dense heads and with axillary peduncles are those with narrow 
leaflets A. Lemmoni, from California, Esperanze from central Mexi- 
co, and Chapalanus from Jalisco. Plants with similar flowers but 
broad leaflets sessile in spikes and pods about sessile have two 
groups, with pods about linear which embrace A. Hartwegi from cen- 
tral Mexico, A. militaris from Chihuahua and adjacent Arizona, A. 
Saltonis from the State of Mexico, A, vaccarum from Arizona and - 
Chihuahua and southward on dry hills, and the conspicuously con- 
