OF THE WASATCH REGION 33 



2. D. caroliuiaiia micraiitha (Nutt.) Gray. (D. micrantha 

 Nutt.) Distinguished from the . type by the minutely-hairy 

 pods. The petals are often lacking. 



3. D. eimeifolia Nutt. Winter annual on short leafy stems. 

 Leaves obovate, wedge-shaped or the lowermost spatulate; 

 loosely stellate-pubescent; sparingly dentate. Raceme some- 

 what lengthened in fruit. Petals white, 2-3 times longer than 

 the sepals; notched at the apex. Style none. Pods minutely 

 hairy. March -April. 



4. D. iiemorojsa L. Winter annual, loosely-stellate pubescent, 

 3-12 inches high. Leaves narrowly-ovate to lanceolate; more 

 or less toothed. Racemes lengthened. Petals notched at apex; 

 yellow, fading to white. Style none. Pedicels horizontal or 

 widely spreading; twice as long as the pods. Dry hills. 

 April-June. 



5. ARABIS. Rock Cress. 



Glabrous or pubescent herbs. Leaves simple. Inflorescence 

 a raceme, sometimes corymbose at the summit. Flowers white 

 or purple. Silique linear, flat; its valves usually 1-neryed, not 

 elastically dehiscent at maturity. Seeds winged or wingless; 

 in 1 or 2 rows in each cell. 



biliques reflexed; style wanting 1. A. Holboellli 



Siliques erect or spreading. 

 Flowers white or whitish. 



Style wanting; flowers yellowish-white... 2. A. glabra 



Style very short; flowers white 3. A. hirsuta 



Flowers rose-purple or pink 4. A. mlcrophylla 



1. A. Holboellii Hornem. (A. retrofracta Graham.) A stel- 

 late-pubescent (rarely glabrous) biennial or perennial with 

 simple or branching stems, y 2 -2 ft. high. Basal leaves spatu- 

 late; entire or slightly dentate. Petals white, pink or pink- 

 purple, twice as long as the sepals; becoming reflexed. Silique 

 long, somewhat curved. Seeds in 1 or 2 rows. (Includes A. 

 exilis A. Nelson, a form with a simple stem not woody at base 

 and seeds in 2 rows; A. lignipes A. Nels., with slender usually 

 simple stems woody at base and seeds in 1 row; A. rhodantha 

 Greene (A. consanguinea Greene) with stout simple stems and 

 seeds in 1 row; and A. lignifera A. Nels. with woody stem 

 branched from the base and seeds in 1 row.) April-June. In 

 the mountains and on dry plains, often among sage-brush. 



2. A. glabra (L.) Bernh. (A. perfoliata Lam.) Tower Mus- 

 tard. An erect biennial. Stems 2-4 ft. high, glabrous and 

 glaucous above, often hirsute below. Basal leaves petioled, 

 2-10 inches long; narrowly oblanceolate and coarsely dentate 

 or even lyrate. Stem leaves sagittate, entire, clasping. Ra- 

 ceme simple; many-flowered. Siliques narrow, erect, closely- 

 appressed. Seeds in 2 rows. May-June, in light shade in moist 

 places. 



3. A. hirsuta (L.) Scop. An erect, rough -hairy or nearly 

 glabrous biennial, 1-3 ft. high; unbranched or nearly so. Basal 

 leaves with margined petioles; oblanceolate to spatulate; 

 usually toothed; clustered. Stem-leaves sessile, clasping; 

 lanceolate or elliptical; auricled at base. Raceme simple, 

 many-flowered. Petals white or greenish-white. Siliques (and 

 pedicels) erect. Seeds with very narrow margins; in 1 row 

 when mature. 



