19 



pitate species with larger flowers come next. A. Coltoni with pur- 

 ple flowers belongs to the Navajo Basin slopes. A. stenophyllus and 

 Antiselli with white flowers come next, belonging to the mountain 

 slopes of the northern Great Basin, the Columbia Basin, and the 

 southern California plains in warmer regions, and almost connecting 

 with the Inflati through A. oxyphysus. Another offshoot of the north- 

 ern Sierras is in A. Californicus and inversus. 



The second branch of the Homalobi has the ventral suture less 

 arched than the dorsal for the most part, and as a whole belongs in 

 warmer regions or at the south. A. campestris with pods wider above 

 Is cosmopolitan In the mountains, even reaching alpine places. A. 

 Pasqualensis Is placed here for lack of a better place, but its posi- 

 tion is not determined. It is from the far south in Mexico. The 

 Bpecies with pods not wider above are A. junceus and EJpiscopus. 

 Species much as In A. campestris but with acerose leaflets are A. 

 simpliclfolius and detritalis. A marked differentiation of the group 

 now comes in the species A. montanus which connects campes- 

 tris with the humistratus group, and represents the alteration of 

 campestris to thrive on the dry plains and stony forests of Wyoming 

 to Arizona. A. humistratus and sesquiflorus represent a modification 

 of montanus for the forests of Arizona and New Mexico to Mexico. 

 Other modifications are A. sericoleuciis for the Plains of Wyoming 

 and Colorado, A. Gilensis for those of the Gila. A. tegetarioides for 

 those of Oregon. A. quinqueflorus and Pueblae are Mexican out- 

 liers. 



2. Triphylli. This group of two species represents a special 

 adaptation to the wind-swept Plains. 



3. Debiles. This offshoot of the Homalobi starts off near A. 

 tenellus and its lowest species doubtless is A. debills connecting the 

 group with A. tenellus of the Homnlobi, nnd also not greatly re- 

 moved from A. pauciflorus of the Inflati. Then comes A. 

 Yukonensis, and leptaleus, with A. polaris last. This little known 

 species is very likely to belong with A. alpinus. The Debiles all 

 belong in the north in cold regions in moist places with sweet or 

 acid soil. 



4. Sparsiflori, This group connects almost direct with the De- 

 biles by A. leptaleus through A. sparsiflorus, with A. obcordatus next 

 and A. villosus last, and belongs on the plains and prairies from Colo- 

 rado BOutheastward. 



5. Alpini. This group Is perhaps as well placed as an offshoot 

 of the Sparsiflori and closely related to the Inflati, though it is re- 

 lated to the Atrati and Strigulosi which represent it in the south. 

 Its lowest species is doubtless A. eleg.ins though the little known A. 

 Crormani may be first, then comes the large stipuled forms A. alpinus 

 .'^nd Americanus. and the small-stiptileri forms aboriginum and Cot- 

 toni. all with a slightly produced dors.-^l suture, then we come to the 

 sulcate and variably 2-celled forms A. Lnbradoricus and andinus. All 

 this grouji belong in the high region or the far north, mostly in 

 cold meadows and copses. 



6. Inflati. This is an early offshoot of the Debiles or coordi- 

 nate with it as an offshoot of the Homalobi, for A. pauciflorus is 

 certainly closely related to A. tenellus. This is a group of the hot and 

 variably alkaline deserts for the most part. Its two primitive species 

 A. pauciflorus and miser belonging in sweet soil in the pine forests 

 of the north. Among its single-celled small podded forms A. Pulsi- 

 ferae and diurnus belong in the sagebrush benches of the southern 

 Columbia Basin drainage and vicinity, A. pubentissimus in the Navajo 

 Basin deserts In sandy places. A. sabulonum in similar places along 

 the Colorado in Utah and Nevada, A. aridus in the hot deserts of the 

 Death Valley-Mojave region, A. Geyeri on the sandy deserts of the 

 Great Basin, A. Julianus. prorlferus and metanus in the deserts of 

 Lower California. A. Vaseyi, Thurberi and Palmeri in the deserts of 



