246 RypBERG: STUDIES ON THE Rocky MounTAIN FLORA 
late, silky and silvery on both sides, about 3 cm. long: raceme 
1—2 dm. long, lax: flowers scattered ; pedicels and calyx densely 
pubescent with short strictly appressed silky hairs; lower lip of 
the calyx about 5 mm. long, lanceolate, almost twice as long as 
the short ovate upper one: corolla yellow or light pink ; banner 
slightly exceeding the wings, with a few short hairs on the back, 
with a darker spot, about 8 mm. long: pods densely silky pubescent. 
This species is nearest related to Z. sulphureus, but differs in 
the more silvery pubescence, the smaller flowers and the appressed 
pubescence of the calyx and pedicels. The type grew at an alti- 
tude of 1900 m. 
Wyomine: Spread Creek, 1897, F. Tweedy, 271 (type in 
herb. N. Y. Bot. Garden). 
