366 BRASSICACEAE 



1 mm. wide. Thclypodium elegans M. E. Jones. Sandy soQ and adobe plains: 

 Colo. — Utah. Submont. My-Je. 



2. T. Bakeri (Greene) Rydb. Stems several, branched, 2-4 dm. high, 

 sparingly hairy at the base; basal leaves petioled, oblanceolate, denticulate, 

 2-4 cm. long; stem-leaves 1-2 cm. long, glabrous and glaucous, ovate; petals 

 white, 6-8 mm. long; pod about 1.5 mm. thick, torulose. Thelypodium Bakeri 

 Greene. Valleys: Colo. Suhmont. My-Je. 



3. T. wyomingensis (A. Nels.) Rydb. Stem single or several, branched, 

 2-5 dm. high, glabrous or nearly so; basal leaves obovate or oblanceolate, toothed, 

 2-5 cm. long; cauline leaves glaucous, ovate or oblong, 4—7 cm. long; petals white, 

 sometimes pinkish, 10-12 mm. long; pod nearly sessile, 1.5 mm. wide. Strep- 

 tanthus wyomingensis A. Nels. Dry desert regions: Wyo. — Utah — Colo. 

 Son. — Suhmont. Je. 



4. T. aurea (Eastw.) Rydb. Stem 3-10 dm. high, branching, sparmgly 

 retrorse-hairy at the base; basal leaves oblanceolate, dentate, with margined 

 petioles; cauline leaves ovate, entire, glaucous; sepals and petals yellow; petals 

 about 8 mm. long; pod 4-7 cm. long, somewhat over 1 mm. wide. Thelypodium 

 aureum Eastw. Arid regions: Colo. Submont. Je. 



49. HETEROTHRIX (B. L. Robins.) Rydb. 



Slender biennials, more or less pubescent, at least below, with stellate or 

 branched hairs. Basal leaves oblanceolate, more or less toothed; stem-leaves 

 lance-linear or linear, entire. Racemes elongate, slender. Calyx more or less 

 oblique, the lower sepals being longer than the upper, all ascending, rather firm 

 and more or less purplish. Petals oblanceolate or spatulate, indistinctly or 

 broadly clawed. Filaments subulate; anthers linear, sagittate at the base, 

 spirally curved. Pod slender, terete, sessile; stigma minute, entire or slightly 

 lobed, the lobes expanding over the septum; cotyledons obliquely incumbent. 

 [Thelypodium § Heterothrix B. L. Robins.] 



1. H. micrantha (A. Gray) Rydb. Stems branched, 3-6 dm. high; basal 

 leaves 2-5 cm. long; upper stem-leaves linear, often glabrate; raceme elongate, 

 narrow; petals 3-4 mm. long, cuneate-spatulate; pedicels and pods erect, the 

 latter 3-4 cm. long, less than 1 mm. thick. Thelypodium micranthum A. Gray. 

 Mountains: Colo. — Tex. — Ariz.; Mex. Son. — -Submont. Jl-0. 



50. HESPERIDANTHUS (B. L. Robins.) Rydb. 



Erect, slender, glabrous perennials, with pale foliage, corymbosely branched 

 above. Basal leaves obovate, toothed; stem-leaves linear, entire. Sepals 

 rather firm, erect, the outer strongly saccate at the base. Petals purple, with 

 obovate blades. Anthers linear, sagittate at the base, strongly curved. Stigma 

 conical or ovate, neither truncate nor 2-lobed. Pod terete, linear, short-stipitate. 

 [Thelypodium § Hesperidanthus B. L. Robins.] 



1. H. linearifolium (A. Gray) Rydb. Stem erect, 6-15 dm. high; basal 

 leaves 5-10 cm. long, oblanceolate or spatulate, thick, pale; stem-leaves sessile, 

 linear, entire; petals purplish, 12-15 mm. long; pedicels in fruit 1-2 cm. long; pod 

 5-10 cm. long, 1.5 mm. wide. Slreptanthus linearifolius A. Gray. Thelypodium 

 linearifolium A. Gray. Dry hills and plains: Colo. — Tex. — Ariz.; Mex. Sub- 

 mont. — Mont. F-Je. 



51. THELYPODIUM Endl. 



Perennial, biennial, or annual leafy-stemmed plants. Flowers perfect, in 

 elongate racemes. Sepals oblong to linear, erect, scarcely gibbose at the base. 

 Petals white or purplish, with a well-developed blade, clawed. Stamens with 

 long, slender, exserted filaments; anthers linear, sagittate at the base, curved 

 and twisted. Pods slender, linear, more or less distinctly stipitate, terete; 

 stigma entire or nearly so, truncate. Cotyledons incumbent. 



Upper leaf-blades auriculate at the base. 

 Pods 3-5 cm. long. 



Petals 6-9 mm. long, about twice as long as the sepals. 



