Family: Brassicaceae
tower rockcress
[ Arabis glabra (L.) Bernh., moreArabis glabra var. furcatipilis M. Hopkins, Arabis glabra var. glabra] |
Plants (3-)4-12(-15) dm, sparsely to densely pilose basally, glabrous distally, trichomes simple and short-stalked, forked. Basal leaves: blades spatulate, oblanceolate, or oblong, (4-)5-12(-15) cm × 10-30 mm, apex obtuse, surfaces usually pubescent, rarely glabrous. Cauline leaves: blade lanceolate, oblong-elliptic, or ovate, 2-9(-12) cm × (5-)10-25(-40) mm, apex acute. Fruiting pedicels appressed to rachis, (6-)7-16(-20) mm, glabrous. Flowers: sepals (2.5-)3-5 × 0.5-1.2 mm, glabrous; petals 5-8.5 × 1.3-1.7 mm; filaments slender, median pairs 3.5-6.5 mm, lateral pair 2.5-4.5 mm; anthers 0.7-1.5 mm. Fruits (3-)4-10(-12.5) cm × 0.7-1.5 mm; style 0.5-0.8(-1) mm. Seeds 0.6-1.2 × 0.5-0.9 mm. 2n = 12, 16, 32. Flowering Apr-Jul. Forest margins, fields, roadsides, stream banks, disturbed sites, mountain slopes, woods, meadows; 0-2800 m; Alta., B.C., Man., N.B., N.W.T., Ont., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Maine, Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.Mex., N.Y., N.C., Ohio, Oreg., Pa., S.Dak., Tenn., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Europe; sw Asia; n Africa; introduced in Australia. Biennial or short-lived perennial 3-15 dm; stem commonly hirsute below with mostly simple (sometimes bifurcate) hairs, glabrous and glaucous above; lower lvs commonly with Y-shaped hairs; cauline lvs overlapping below, more remote above, all lanceolate or lance-oblong, auriculate-clasping, usually glabrous and glaucous; pet 3-6 mm; style 1-1.5 mm; mature pedicels erect, 7-16 mm; frs erect, subterete, 5-9 cm נ0.8-1.3 mm, the valves with prominent midnerve reaching nearly or quite to the tip; seeds in 2 rows in each locule, angular, very narrowly winged; 2n=12. Usually in dry soil; circumboreal, in Amer. s. to N.C., Ark., Kans., N.M., and Calif. May, June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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