MUSTARD FAMILY 327 



medium pubescens Greene. River banks and waste places: Colo. Utah Mex. 

 Son. -Mont. Ap-Au. 



19. L. ramosum A. Nels. Biennial; stem 1.5-3 dm. high, minutely granu- 

 lar- puberulent; basal leaves oblanceolate, coarsely serrate or pinnatifid; upper 

 cauline leaves narrowly oblanceolate or linear, entire; petals about 1 mm. long; 

 stamens 2; capsule orbicular, 3 mm. long, narrowly winged at the summit. 

 Sandy soil: Mont. Colo. Submont. Mont. Je-Au. 



20. L. simile Heller. Annual; stem 3-5 dm. high, more or less puberulent, 

 lower leaves oblanceolate, pinnately lobed or parted, puberulent; upper stem-leaves 

 entire, oblanceolate to linear; petals greenish white, 1.5 mm. long; stamens usually 

 2; pod fully 3 mm. long, winged above, obovate, notched, puberulent on the 

 margin. River banks: Ida. Wash. B.C. Son. My-Jl. 



21. L. ramosissimum A. Nels. Biennial; stems 2-4 dm. high, slightly 

 puberulent, profusely branched; basal leaves pinnately lobed or toothed or in- 

 cised; stem -leaves oblanceolate, all except the uppermost more or less toothed; 

 petals white, narrowly spatulate; stamens 2; pod ovate, 3 mm. long. Mesas 

 and mountains: Colo. Wyo. Submont. Mont. Je-Au. 



22. L. divergens Osterh. Biennial; stems 1.5-3 dm. high, branched from 

 the base, minutely puberulent; basal leaves spatulate, coarsely toothed; stem- 

 leaves linear or oblanceolate, few-toothed above or entire; petals none; stamens 

 2; pod elliptic, 3 mm. long; fruiting racemes numerous and short. Mountains: 

 Colo. Utah. Submont. Mont. Jl. 



23. L. elongatum Rydb. Annual or biennial; stem branched near the base, 

 about 3 dm. high, granular-pruinose above; basal leaves spatulate or oblanceo- 

 late, about 4 cm. long, coarsely toothed; stem-leaves oblanceolate, entire or with 

 a few small teeth, acutish; petals minute, linear-oblanceolate, or lacking; pods 

 nearly orbicular, about 3 mm. broad, glabrous or slightly pruinose. Sandy soil 

 and rocky hilltops: Ida. Wash. Son. My-Je. 



24. L. densiflorum Schrad. Annual or biennial; stem 2-5 dm. high, 

 puberulent, with short hairs, simple below, branched above; basal leaves ob- 

 lanceolate or oblong, deeply incised-serrate or more or less pinnatifid, puberu- 

 lent; stem-leaves mostly sharply toothed; petals rudimentary, linear-oblong, or 

 none; stamens 2 or 4; pod obovate, about 3 mm. long. L. apetalum A. Gray, 

 not Willd. Plains, prairies, waste places: Hudson Bay Vt. N.Y. N.M. 

 B.C. PlainMont. Ap-O. 



26. L. pubecarpum A. Nels. Annual; stem usually branched near the base, 

 8-30 cm. high, minutely puberulent; basal leaves oblanceolate, toothed; stem- 

 leaves linear or oblanceolate, entire, or the lower remotely toothed; petals want- 

 ing; stamens 2; pod finely pubescent, broadly oval to orbicular, 2.5-3 mm. long. 

 Dry rocky slopes and roadsides: Mont. Wyo. Utah Nev. My-Jl. 



26. L. Georginum Rydb. Apparently biennial, 1-2 dm. high; stems hir- 

 sute with short spreading hairs; lower leaves 1-5 cm. long, deeply pinnately 

 divided with ovate lobes, more or less pubescent; petals spatulate, slightly ex- 

 ceeding the sepals; pods pubescent, rarely almost glabrous, rounded oval, 4 mm. 

 long, broadly winged above, forming at the apex two broadly ovate obtuse 

 lobes, over 0.5 mm. long. L. lasiocarpum Coult. & Nels., not Nutt. L. Wrightii 

 Auth., not A. Gray. Arid regions: w Colo. -Ariz. Nev. Son. Ap-Je. 



27. L. Fletcher! Rydb. Annual or biennial; stem erect, 3-5 dm. high, 

 puberulent with short cylindric spreading hairs; leaves narrow, pinnatifid, with 

 linear divisions or saliently toothed, 2-5 cm. long, puberulent; petals none; 

 stamens usually 2; pod glabrous, scarcely 3 mm. long, obovate in outline, gla- 

 brous; lobes of the wings nearly 0.5 mm., triangular-ovate, acutish or obtuse. 

 Roadsides: Man. Sask. Plain. 



28. L. Bourgeauanum Thellung. Annual or biennial; stems decumbent, 

 1-1.5 dm. long; leaves linear or narrowly linear-spatulate, entire, pubescent 

 with thickened hairs; petals rudimentary; stamens 2; pod obovate or elliptic, 

 deeply notched at the apex; lobes of the wings acute and somewhat porrect. 

 Plains: Sask. Plain. 



