54 
Spring Flora of Oklahoma 
mens 1-6. Pods short, terete or nearly so. Valves nerve¬ 
less or 1-nerved. Style short or slender. Stigma 2-lobed 
or nearly entire. Seeds in 2 rows in each cell or sometimes 
in 1 row. 
1. Radicula obtusa (Nutt.) Greene. Blunt-leaved Yellow- 
cress. Annual or biennial, diffuse, the branches ascending or erect. 
Leaves oblong or oblanceolate, pinnately-divided, or pinnatifid, the 
lobes obtuse, repand-toothed, or sometimes entire. Pedicels l"-2" 
long. Flowers yellow, 1" broad or less. Pods narrowly oblong, or 
linear, 3"-5" long, ascending. 
In low ground. April-August. Oklahoma County. 
VI. SISYMBRIUM (Tourn.) L. 
Aquatic herbs with pinnately-divided leaves, and small 
white flowers in terminal racemes. Pods linear to linear- 
oblong, slender pedicelled, tipped with a rather stout style, 
the valves nerveless. Seeds in two rows in each cell of the 
pod. 
1. Sisymbrium Nasturtium-aquaticum L. True Water-cress. 
Glabrous, branching, floating or creeping, rooting from the nodes. 
Leaves of 3-9 segments, all obtuse, ovate or oval or the terminal one 
nearly orbicular. Flowers in racemes. Petals twice the length of 
the calyx. Pods 6"-16" long, 1" wide, spreading and slightly curved 
upward, on pedicels of about their length. 
In brooks and streams. April-November, Wichita and Arbuckle 
Mountains and Cleveland County. 
VII. LEPIDIUM. (Tourn.) L. 
Erect, diffuse, glabrous or pubescent herbs. Leaves en¬ 
tire, toothed or pinnately divided. Flowers in terminal 
racemes, small, white. Petals short, sometimes wanting. 
Stamens 2, 4 or 6. Pod rounded or obcordate, flattened 
contrary to the partition. 
Stem-leaves clasping by an auriculate base. 
1. L. Draba. 
Stem-leaves petioled or sessile, not clasping. 
Pods slightly winged above, orbicular or oval, about 1" 
broad; petals present or none. 
