286 CRUCIFERAE 
2. C. hirsuta, L. (Fig. 8, pl. 57.) Harry Birrer Cress. Whole 
plant hairy. Leaves nearly all basal, feather-formed, with usually about 
5 leaflets, the terminal one orbicular or nearly so, the other more or less 
oval or oblong. Stem leaves few, their segments linear. Flowers white, 
pods erect, linear. Moist places, Penna., south and west. March-May. 
3. C. pennsylvanica, Muhl. (Fig. 4, pl. 55.) PENNSYLVANIA BITTER 
Cress. Stem 8 in. to 3 ft. high, leafy up to the clusters of flowers; 
leaflets of lower leaves rounded, of upper narrow; terminal leaflet pear- 
shaped with conspicuous notch on each side. Leaflets of all leaves from 
4 to 8 pairs. Flowers small, white. Swamps and wet places. April. 
June. 
4. C. arenicola, Britton. Sanp Birrer Cress. Stem usually much 
branched, 4 to 1 ft. high. Leaves compound of 4 or more pairs of linear 
leaflets, the terminal one Jong and narrow. Flowers white, about 1/6 in. 
across. Wet sandy soil. March-April. 
5. C. parviflora, L. SMALL-FLOWERED BITTER Cress. Somewhat simi- 
lar to No. 3, but leaflets less numerous, the stem less branching and 
flowers smaller. Stem very slender. Dry rocky places. April-May. 
6. C. flexuosa, With. Woop Birrrr Cress. Stem 6 to 15 in. high, 
rather stout; lateral leaflets narrow but broadest toward apex, about 
3 pairs, the terminal one pear-shaped or orbicular. Wet woods and 
along streams. May-Aug. 
7. C. bellidifolia, L. (Fig. 3, pl. 57.) Atpine Cress. A dwarf 
species on the White Mountains and other elevations. Leaves ovate, the 
lower on long, the upper on short foot-stalks. Flowers few, white. July. 
8. C. purpurea, (Torr.) Britton. (Fig. 2, pl. 56.) PURPLE CREss. 
Stem not branched, 6 to 15 in. high. Basal leaves orbicular, heart- 
shaped, on long slender foot-stalks; upper, broad, with coarse toothed 
borders and without foot-stalks. Flowers purple. Cold wet places. April- 
May. 
9. C. bulbosa, (Schreb.) BSP. (Fig. 5, pl. 55.) Bursous Cress. 
Stems not branching, 4 to 14 ft. high. Lower leaves orbicular heart- 
shaped on long slender foot-stalks. Upper, broad and dentate without 
leaf-stalks. Flowers white. Wet places. April-June. 
10. C. rotundifolia, Michx. Rounp-LEAveD WATER Cress. Stem weak, 
often rooting at the joints and sending out runners. Leaves rounded, 
somewhat angled; sometimes heart-shaped. Flowers white. In cold 
springs in the southern part of our area. 
22, DRABA, L. 
Small herbs growing mostly in tufts; leaves and stems hairy with 
forked hairs; stems generally with few or no leaves, the leaves, which 
may be toothed or not, arranged in a rosette at the base. Flowers in 
elongated or rounded clusters, small, and in our species, white. Pods 
oval, or linear, flat, oblong, pointed at the apex, few to many seeded. 
Seeds arranged in two rows in each valve. 
Pétala io-cleftsevle ba: 5: oe) vee Xe REMI eer Us) hors ela meee 
Petals not notched or cleft. i 
Leaves elliptic, margin without teeth or notches . . D. caroliniana 
Leaves oblong, margins with teeth . . . . - + + «+ Dz. incana 
