Arabis L.

Herbs, annual, biennial or perennial, glabrous or pubescent; hairs simple, medifixed, forked or stellately branched; stems erect, often simple. Basal leaves in a rosette, spathulate, stalked and hairy; cauline sessile, amplexicaul, entire or toothed. Racemes usually (in fruit), bracteate or ebracteate. Flowers white, purple or rose-coloured. sepals erect or spreading, short, often slightly saccate at base. Petals obovate-oblong, entire, usually clawed, longer than sepals. Stamens 6; filaments not appendaged; anthers oblong-linear. Ovary linear, many-ovuled; style distinct; stigma capitate or emarginate. Fruits linear-oblong, usually compressed; valves veiny with weak midrib; style short; seeds usually ovate, compressed, more or less winged.

Chiefly in Northern temperate zone and S. America; about 100 species, 9 in India.

KEY TO THE SPECIES

1a. Cauline leaves either auricled or amplexicaul to subamplexicaul at base

2

b. Cauline leaves neither auricled nor amplexicaul at base

7

2a. Seeds either margined or narrowly winged

3

b. Seeds neither margined nor winged

5

3a. Fruits pubescent

3. Arabis nova

b. Fruits glabrous

4

4a. Flowers ca 10 mm across

2. Arabis bijuga

b. Flowers ca 5 mm across

5. Arabis pterosperma

5a. Basal leaves entire

6. Arabis recta

b. Basal leaves toothed or crenate-serrate

6

6a. Basal leaves 3 - 4 cm long; flowers ca 5 mm across

4. Arabis pangiensis

b. Basal leaves 5 - 15 cm long; flowers ca 9 mm across

1. Arabis amplexicaulis

7a. Cauline leaves ca 0.5 cm long, linear or absent

7. Arabis saxicola

b. Cauline leaves 0.8 - 2 cm long, usually oblong-obovate, toothed or lobulate

8

8a. Fruits ca 8 cm long; style ca 2 mm long

8. Arabis tenuirostris

b. Fruits ca 6 cm long; style ca 1.5 mm long

9. Arabis tibetica

List of Lower Taxa