Teesdalia nudicaulis (L.) W. T. Aiton
Family: Brassicaceae
barestem teesdalia,  more...
Teesdalia nudicaulis image
Stems 0.5-1.5(-2) dm. Basal leaves: petiole 0.5-2.5(-3.5) cm; blade oblanceolate to obovate in outline, 0.3-1.5(-2) cm × 2-4(-7) mm, margins usually lyrate-pinnatifid, rarely dentate or entire; lateral lobes obtuse. Cauline leaves 0-4; blade linear to oblong. Fruiting pedicels 3-7 mm. Flowers zygomorphic ; sepals 0.5-0.8 (-1) × 0.4-0.6(-0.8) mm; petals oblong to obovate, abaxial pair 1.5-2.5 × 0.6-1 mm, adaxial pair 0.5-1 × 0.3-0.4 mm; stamens 6, tetradynamous; filaments 0.8-1 mm, (basal appendage white, ca. 1/2 its length); anthers 0.1-0.2 mm. Fruits 3-4.5 × 3-4.5 mm; style ca. 0.1 mm. Seeds 1-1.2 × 0.9-1 mm. 2n = 36. Flowering Apr-Jun. Sandy areas along trails, near beaches, pine clearings, waste grounds, fields, roadsides, gravelly slopes; 0-300 m; introduced; B.C.; Calif., Conn., Md., Mass., Mich., N.J., N.Y., N.C., Oreg., Pa., S.C., Va., Wash.; Europe; Asia (Middle East); introduced also in South America (Chile), nw Africa, Australia.
Annual herb 5 - 20 cm tall Stem: occasionally short-hairy. Flowers: 2 mm wide, in small, branched clusters. Sepals four, ascending. Petals four, unequal, white. Stamens six. Fruit: a pod (silique), 3 - 3.5 mm long, broadly egg-shaped, keeled at the margins, narrowly winged. Basal leaves: pinnately divided (lyre-shaped) with rounded lobes, 2 - 5 cm long, spatula-shaped. Stem leaves none or much reduced.

Similar species: No information at this time.

Flowering: late April to mid-June

Habitat and ecology: Introduced from Europe. A weed rarely seen in the Chicago Region. Look for it in disturbed sandy areas.

Occurence in the Chicago region: non-native

Etymology: Nudicaulis means "with leafless stems."

Author: The Morton Arboretum

Pls glabrous or occasionally short-hairy; basal lvs spatulate in outline, 2-5 cm, lyrate-pinnatifid with rounded or obtuse lobes; cauline lvs none or much reduced; stems 0.5-2 dm; fls 2 mm wide; pet unequal, the 2 outer (abaxial) ones well surpassing the sep, the 2 inner half or two-thirds as long, about equaling the sep; stamens 6; fr 3-3.5 mm; style ca 0.1-0.2 mm; 2n=36. Native of Europe, now found here and there in the U.S. as a casual weed. Apr.-June. Iberis amara L. and I. umbellata L., spp. of Candytuft, occasionally escape. They would key to Teesdalia because of their dissimilar pet and short frs flattened contrary to the septum, but they have well developed cauline lvs, longer (5-9 mm) frs, and larger (5-10 mm wide) fls. In I. amara the lvs have a few large teeth and the infl elongates after anthesis; in I. umbellata the lvs are entire and the infl remains short, forming a dense, umbel-like cluster in fr.

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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