(171) 
Family CRUCIFERAE. 
Cardamine pratensis angustifolia Hook. Near mouth of 
Bonanza and mouth of Klondike (Williams). 
Roripa Williamsii Britton, sp. nov. 
Glabrous, about 1.5 dm. high. Leaves about 5 cm. long, 
deeply pinnatifid into oblong, obtuse, entire or toothed seg- 
ments 2-3 mm. wide, the terminal segment much larger than 
the lateral ones; racemes elongating and with very distant 
pedicels in fruit; pedicels spreading, about 1 cm. long; pod 
oblong, obtuse, about 3 mm. long. 
Near mouth of Bonanza Creek, R. S. Williams, June 18, 
1899. 
Arabis lyrata occidentalis S. Wats. Near mouth of Bo- 
nanza (Williams). 
Arabis Holboellii Hornem. White Horse Rapids (Tarle- 
ton). 
Parrya macrocarpa R. Br. The Dome, Klondike-Indian 
Divide (Tarleton). 
Erysimum chetranthoides LL. Dawson (Williams). 
Erysimum angustatum Rydb., sp. nov. 
A more or less cespitose perennial, with a slender tap-root 
and short branched rootstock or caudex. Stems 1-2 dm. 
high, sparingly grayish strigose, obtusely angled; leaves 
very narrowly oblanceolate-linear or linear, 4-7 cm. long, 
I-2 mm. wide, grayish strigose; sepals linear, obtuse, about 
8 mm. long, two alternate ones deeply saccate at the base, 
pale yellowish; petals lemon-yellow, about 14 mm. long; 
pods 5-8 cm. long, about 1.5 mm. broad, obtusely angled, 
ascending on ascending pedicels 5-8 mm. long, with a dis- 
tinct beak 3-5 mm. long, somewhat constricted between the 
seeds; cotyledons incumbent. 
This species is probably nearest related to &. asperzmum 
(Chetranthus asperrimus Greene) but differs in the more 
elongated branches of the caudex or rootstock, which are 
covered with remnants of old leaves, the narrower perfectly 
entire leaves, the more slender stem, the less sharply angled 
pod and the more evident beak. ‘The type was collected at 
Dawson by R. S. Williams, July 13, 1899. 
