Studies in the genus Lupinus—I. A new species of the subgenus 
Platycarpos 
CHARLES PIPER SMITH 
I have recently made a critical study of the material usually 
determined as either Lupinus microcarpus Sims or L. densiflorus 
Benth., and have prepared an illustrated paper, monographic in 
scope, giving in detail my conclusions and a new classification. 
As conditions beyond my control prevent the prompt publication 
of this work, I deem it expedient to publish at once a preliminary 
paper. i 
Heller (Muhl. 8:87. 1912) has already proposed a separation 
of the subgenus Platycarpos into two sections, applying the group- 
name ‘‘PusILL1”’ to the loosely flowered small species of the Mexi- 
can Plateau, the Great Basin, and the Rocky Mountain region. 
The verticillate and commonly larger plants of the Pacific Slope 
should accordingly be assembled into a group that would properly 
bear the name ‘‘ MICROCARPI.” 
The published names of members of this group indicate twelve 
species and one variety. Of these L. microcarpus Sims, L. denst- 
florus Benth., L. luteolus Kell., and L. malacophylius Greene are 
recognized as species by authors generally and are accepted by me 
L. horizontalis Heller I am also able to accept as a species; but the 
other names, except for two which are acknowledged as synonyms, 
I must use as representing varieties of either L. microcarpus or 
L. densiflorus. 
Most of the North American plants commonly determined as 
L. microcarpus, however, I am not able to accept as Sims’ species, 
and in order to draw a more satisfactory line of distinction between 
the initial species of Sims and Bentham, and, at the same time do 
justice to a group of unnamed variations that I deem worthy of 
recognition, I propose the following species as new: 
Lupinus subvexus sp. nov. 
Eramosus vel ramosus, 20-40 cm. altus, caule cum eramoso 
plerumque elongato foliis sparsis, villoso pilis 2-4 mm. longis: 
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