and near A. junceus and verges toward the Alpini and represents 

 it in the south and warmer and drier regions. It has a tendency 

 to fleshy or coriaceous pods, and with ventral suture the more 

 arched. A. Salmonis is a fleshy and caespitose plant of cold ridges 

 in the Blue Mountains Oregon, A. obscurus has much narrower and 

 less fleshy pods and frequents the sagebrush benches of northern 

 Nevada. A. atratus has about straight pods and is very variable. 

 It belongs in the sagebrush-juniper regions. In the Boise region its 

 pods are papery and its filiform stems straggle for several feet over 

 the ground, in central Nevada its stems are spreading and short and 

 pods chartaceous to almost coriaceous, in the Death Valley region 

 its pods are almost fleshy and rather cartilaginous. A. Ibapensis is 

 like the central Nevada atratus but with different leaves and grows 

 in the Deep Creek mountains on sagebrush slopes. A. Panamin- 

 tensis has quite fleshy pods, but they on drying are only chartaceous. 

 It grows in the rocky canons of the Panamints of California. 



17. Striguiosi. This group seems to be an early branch of th^ 

 Atrati and like it has the ventral suture the more arched, and th« 

 rods are almost always stipitate and papery and inclined to inflated, 

 and reflexed. A. recurvus and straturensis are in close relation with 

 their narrow and linear, not inflated pods and acuminate base, and 

 papery partial partition. They frequent the Grand Canon region, 

 among the pines and brush. The rest of the group has oblong to glo- 

 bose pods either inflated or appearing so. A. strigulosus has pods 

 acuminate at base and often at tip and with loose pubescence, and 

 in its various forms extends from the Grand Canon to southern 

 Mexico. A. Brandegei, platytropis and Cobrensis are peculiar species 

 the first and last seemingly inflated but little if at all so, and little 

 If at all stipitate; the first reminds one of atratus, of the Atrati and 

 may belong there near the Idaho form of atratus, and it grows from 

 Canon City Colorado through the Navajo basin in the Lower Tem- 

 perate life zone. A. Cobrensis is more coriaceous and frequents the 

 mountains of New Mexico and Arizona in the same zone. A. platy- 

 tropis a very aberrant species of the dry mountains of eastern 

 Nevada, Montana and the Sierras doubtless closest related to A. 

 Brandegei. This rarely gets as low as the Lower Temperate life 

 zone, and has globose and greatly inflated pods. Plants with pros- 

 trate stems or nearly so and elongated, and with stipitate pods, and 

 plants almost wholly smooth grow in the meadows much as the 

 Alpini but in central and southern Mexico. These are A. Guatama- 

 lensis, Pamteri. Tolucanus and Rosei. A. .similar species but creep- 

 ing and rooting at the nodes is A. reptans. 



18. Flexuosi. This goes off earlier than the Cellini from the 

 Homalobi in the tendency of the pods to be coriaceous and round in 

 cross section, and in the small flowers of the parent group. The 

 parent species is A. flexuosus of the northern Plains. A. parviflorus 

 is a depauperate modification of the Plains, from which branch off 

 the Ocreati. Then the species become inflated and the flowers lar- 

 ger and we have a natural series to the end, as the species extend 

 southward. A. gracilentus connects this series with the parent and 

 belongs in the dry pinon forests of Colorado and New Mexico. A. 

 Sileranus is a straggling offshoot of the Kaibab region. . A. coriaceus 

 and Antoninus belong in the hotter regions of Mexico, and A. pin- 

 onis in the Sevier Basin Utah. 



19. Argo"hy!li. This is a natural offshoot of the Flexuosi in the 

 line of pod thickening. A. desperatus of the hot ledges of the Navajo 

 Basin is a near relative. A. cibarius of the sagebrush plains from 

 Montana to southern Utah and westward is next, then come A. io- 

 danthus an! Webberi of the Sierra region. These are forms with little 

 pubescence except in A. desperatus. Forms with mostly large pods 

 quite fleshy and not inflated noticeably and with silvery pubescence 

 not woolly are A. argophyllus of the Montana to Arizona slopes and 

 plains. Shortianus of the Colorado and New Mexican plains and foot- 



