26 CRUCIFERJS. (MUSTARD FAMILY.) 



4. LEAVENWORTHIA, Torr. 



Silique oblong or oblong-linear, compressed, often contracted between the 

 seeds. Seeds in a single row in each cell, orbicular, flat, winged. Embryo 

 straight or nearly so. Small annual or biennial herbs, with short 1 - few- 

 flowered steins, piniiatirid leaves, and yellow, white, or purplish flowers, on 

 elongated pedicels. 



1. L. tUircll, Torr. Leaves mostly radical, with 4-8 oblong toothed lobes, 

 the terminal one larger and rounded ; raceme at leugtlj, 4 - 10-flowered ; stvle 

 manifest ; embryo straight. ( hi flat rocks in the upper districts of Alabama, 

 and westward. Plant 2' -6' high. Flowers yellow 



2. L. Michauxii, Torr. Leaves as in No. 1 ; flowers mostly solitary, on 

 radical peduncles ; style almost none; embryo slightly curved. (Cardamiue 

 uuiflora, Mich.r.) Rocks, Alabama and Tennessee. Flowers purplish or 

 white. 



3. L. torulosa, Gray. Silique linear, torose ; style fully equalling the 

 breadth of the silique ; seeds broadly oval, narrowly winged ; radicle nearly 

 transverse, strictly applied to the edges of the cotyledons at the base on one 

 side; petals purplish with a yellow base. Cedar barrens, Tennessee (Dr. 

 Gattinger). 



4. L. Stylosa, Gray. Slender, strictly stemless ; silique oval or broadly 

 oblong (4'' long), plane, surmounted by a slender style of fully 2 lines in 

 length ; seeds only 3-6, orbicular, distinctly winged ; embryo as in the pre- 

 ceding ; petals pure golden yellow. With the preceding. 



5. ARABIS, L. 



Silique elongated, linear, flattened ; valves 1-uerved, or finely veined. Seeds 

 numerous, in a single row in each cell, roundish, usually winged or margined. 

 Cotyledons accumbeut. Chiefly annual or biennial herbs. Radical leaves 

 mostly piunatifid ; those of the stem sessile and often cordate or sagittate at 

 the base. Flowers white or rose-colored, in terminal racemes. 



* Silique compressed-Jiliform, erect or spreading ; seeds wing/ess or narrow! t/ 



margined. 



1. A. hirsuta, Scop. Stem slender, erect, pubescent, 2 high; leaves 

 lanceolate or oblong, cordate-clasping, smooth, sparingly denticulate, the 

 radical petioled ; petals white, twice as long as the sepals ; silique (and pedi- 

 cel) erect, 2' long, tipped with the short style ; seed margined. Banks of the 

 Coosa River, Georgia. May. 



2. A. patens, Sulliv. Leaves ovate, coarsely toothed ; pedicels and 

 siliques spreading ; style distinct. Otherwise like the last. River banks, 

 Tennessee (Gattinger). May. 



3. A. dentata, Torr. & Gray. Pubescent and roughish, branching from 

 the base, 1 high ; leaves oblong, toothed, clasping and auriculate at the base, 

 I' -2' long, the lowest obovate, petioled; petals barely exceeding the calyx; 

 silique spreading, 1' long; seed not margined. Rich soil, Tennessee. 

 April. 



