4. Arabis Dentąta T. & G. Toothed Rock-Cress

Fig. 2072

Sisymbrium dentatum Torr. Transyl. Journ. Med. 10: 338. Hyponym. 1837.

Arabis dentata T. & G. Fl. N. A. 1: 80. 1838.

Slender, erect or ascending, 1°-2° high, sparingly branching, finely rough-pubescent. Basal leaves on margined petioles, obovate, dentate, 2'-4' long, obtuse; stem-leaves sessile, clasping by an auricled base, dentate, oblong or oblanceolate, obtuse or the upper acute; pedicels 1"-2" long, spreading; flowers greenish-white, l"-2" broad, the petals hardly exceeding the calyx; pods narrowly linear, 10"-15" long, spreading; style almost none; seeds in 1 row in each cell, oblong, marginless.

Western New York to Minnesota, south to Tennessee, Missouri and Kansas. April-June.

5. Arabis Alpina L. Alpine Rock-Cress. Snow-Drift

Fig. 2073

Arabis alpina L, Sp. Pl. 664. 1753.

Erect or ascending, 4'-12' high, densely and finely pubescent. Basal leaves 1'-2' long, obovate or spatulate, obtuse, dentate, on margined petioles; stem-leaves ovate, sessile, clasping by an auricled base, dentate; flowers white, 2"-3" broad; petals much exceeding the calyx; pedicels slender, spreading or ascending, 4" long in fruit; pods 1' - 1 1/2' long, curved upward, narrowly linear, 1" broad; seeds in 1 row in each cell, oblong, narrowly winged; style scarcely any.

Gaspé, Quebec, to Labrador, arctic America and Alaska. Also in northern and central Europe and in northern Asia. White allison. Bishop's-wig. Dusty-husband. Summer.

5 Arabis Alpina L Alpine Rock Cress Snow Drift 4155 Arabis Alpina L Alpine Rock Cress Snow Drift 416

6. Arabis Pątens Sulliv. Spreading Rock-Cress

Fig. 2074

Arabis patens Sulliv. Am. Journ. Sci. 42: 49. 1842.

Erect, 1°-2° high, mostly pubescent with spreading hairs, at least below. Basal leaves dentate, l' - 3' long, on marginal petioles; stem-leaves 1'-2' long, ovate or oblong, acute or acutish, sessile, dentate or nearly entire, partly clasping by a cordate base; pedicels ascending, 6"-8" long in fruit, slender; flowers white, 4" broad; pods 1'-1 1/2' long, \" broad, narrowly ascending, not appressed; seeds in 1 row in each cell, oblong, narrowly winged; style 1" long.

Eastern Pennsylvania to Minnesota, south to Alabama and Missouri. Summer.

7. Arabis Hirsłta (L.) Scop. Hairy Rock-Cress

Fig. 2075

Turritis hirsuta L. Sp. Pl. 666. 1753.

Arabis hirsuta Scop. Fl. Cam. Ed. 2, 2: 30. 1772.

Arabis ovata Poir. in Lam. Encycl. Suppl. 5: 557. 1817.

Stem strictly erect, nearly simple, 1°-2° high, rough-hairy or nearly glabrous. Basal leaves on margined petioles, obovate or spatulate, obtuse, dentate or repand, 1'-2' long; stem-leaves sessile, clasping by an auricled base, lanceolate or oblong; pedicels nearly erect, or ap-pressed, 3"-6" long in fruit; flowers 2"-3" long, white or greenish-white; petals more or less longer than the calyx; pods narrowly linear, erect or appressed, 1'-2' long, about i" wide; seeds 1-rowed, or when young obscurely 2-rowed, oblong or nearly orbicular, narrowly margined; style very short.

In rocky places, New Brunswick to Yukon, British Columbia, south to Georgia, Missouri, Kansas, Arizona and California. Also in Europe and Asia. May-Sept.

7 Arabis Hirs Ta L Scop Hairy Rock Cress 4177 Arabis Hirs Ta L Scop Hairy Rock Cress 418