266 BRASSICACEAE 



1. Thlaspi arvense L. Field Penny Cress. Fig. 1992. 



Thlaspi arvense L. Sp. PI. 646. 1753. 



Annual, glabrous, the stems erect, 2-5 dm. high, branching above. Basal leaves oblanceo- 

 late, petioled; stem leaves oblong to lanceolate, the lower sessile, the upper auriculate-clasping, 

 sparingly toothed ; pedicels spreading, slender ; flowers white, 2-3 mm. high ; pods suborbicular, 

 8-12 mm. broad, broadly winged all around; style obsolete or nearly so; seeds rugose. 



Sparingly introduced along the coast in the Pacific States. Native of Eurasia. June— Aug. 



2. Thlaspi alpestre L. Alpine Penny Cress. Fig. 1993. 



Thlaspi alpestre L. Sp. PI. ed. 2. 903. 1762. 



Perennial, glabrous, the flowering stems one to several from the short simple or branched 

 caudex, 1-3 dm. high. Basal leaves narrowly to broadly spatulate, 1-4 cm. long, entire or some- 

 what toothed ; stem leaves few, auriculate-clasping, oblong to round-ovate ; pedicels slender, 

 spreading ; sepals white-margined ; petals 4-6 mm. long ; pods 4-7 mm. long, cuneate, obtuse at 

 apex or more commonly truncate, rather broadly refuse and narrowly winged; style 3 mm. 

 long; seeds faintly reticulate. 



Rocky situations, Transition and Canadian Zones; Washington and Montana, south to northern California, 

 New Mexico, and Arizona. Also in Eurasia. Tjpe locality: Austria. June-Aug. 



This is a variable species but satisfactory specific characters are not evident for the recognition of more 

 than one species. Thlaspi calif ornicum S. Wats. (Proc. Amer. Acad. 17: 365. 1882) which was based upon 

 specimens collected at Kneeland Prairie, Humboldt County, California, differs in having the pods acute or 

 acutish at apex, but complete transitions from this form to the truncate and retuse pods are common. Thlaspi 

 glaucum A. Nels. (Bull. Torrey Club 25: 275. 1898) extends westward through the Great Basin region to 

 eastern Washington, Oregon, and northeastern California, but there seems to be no well-defined specific character 

 for its segregation. 



13. COCHLEARIA [Tourn.] L. Sp. PI. 647. 1753. 



Annual or biennial fleshy maritime herbs, with lobed or entire alternate leaves, and 

 small, white, rarely purplish or yellowish racemose flowers. Sepals short and broad. 

 Petals obovate. Style slender; stigma entire or nearly so. Silicle inflated, ovoid or 

 spherical ; valves very convex, dehiscent. Seeds several in each cell, in 2 rows, margin- 

 less ; cotyledons mainly accumbent. [Greek, meaning spoon, from the shape of the leaves.] 



About 25 species, natives of colder parts of the north temperate zone. Type species, Cochlcaria officinalis L. 



1. Cochlearia officinalis L. Spoonwort. Fig. 1994. 



Cochlearia officinalis L. Sp. PI. 647. 1753. 

 Cochlearia oblongifolia DC. Syst. 2: 363. 1821. 



Succulent herb, with decumbent branches, stems 15-30 cm. long. Basal leaves long-petioled, 



oblong to reniform, obtuse, 15-25 mm. long, dentate or entire; upper leaves oblong to ovate, 



sessile or short-petioled ; racemes elongated in fruit; pedicels 6-8 mm. long; petals white, 2-3 



mm. long; pods 4-6 mm. long, smooth or reticulated; valves strongly 1-nerved. 



Along the seacoast, Boreal Zones; generally distributed over arctic North America, Europe, and Asia. On 

 the Pacific Coast extending from Alaska to Oregon. A valued antiscorbutic salad in the far North. Type 

 locality: in Europe. May- July. 



14. SISYMBRIUM L. Sp. PI. 657. 1753. 



Annual or biennial herbs, with alternate dentate or pinnatifid leaves and yellow or 

 white flowers. Pubescence when present of simple hairs. Sepals spreading. Stamens 6. 

 Pods narrowly linear, elongated, terete or nearly so, appressed or divergent, the valves 

 dehiscent. Stigma 2-lobed. Seeds in 1 or 2 rows in each cell, oblong, not winged ; cotyle- 

 dons incumbent. [Ancient Greek name of some crucifer.] 



A genus of about 75 species, natives of the temperate regions of the world. Type species, Sisymbrium 

 altissimum L. 



Siliques erect, sharply acuminate. 1. S. officinale. 

 Siliques spreading, not acuminate. 

 Pedicels of the siliques stout. 



Upper leaves pinnatifid with linear divisions; pods 1 mm. wide. 2. S. altissimum. 



Upper leaves hastate or entire; pods 2 mm. wide. 3. S. orientate. 



Pedicels of the siliques slender; upper leaves coarsely pinnatifid. 4. S. Irio. 



1. Sisymbrium officinale (L.) Scop. Hedge Mustard. Fig. 1995. 



Erysimum officinale L. Sp. PI. 660. 1753. 



Sisymbrium officinale Scop. Fl. Cam. ed. 2. 2: 26. 1772. 



Sisymbrium leiocarpum Jordan, Diag. 1: 139. 1864. 



Stems erect, ^-6 dm. high, more or less pubescent with simple hairs or glabrous. Basal leaves 

 lyrately and somewhat runcinately pinnatifid, 7-15 cm. long, the upper shorter, lanceolate, sub- 

 entire or hastate ; pedicels 2 mm. long, erect in fruit; petals yellow, 3 mm. long; pods 10-15 mm. 

 long, linear, acuminate, erect and closely appressed to the stem in fruit; valves strongly 1-nerved. 



A common wayside weed, naturalized from Europe. April-Aug. 



