Laennecia schiedeana (Less.) G.L. Nesom (redirected from: Erigeron schiedeanus)
Family: Asteraceae
[Conyza schiedeana (Less.) Cronq.,  more...]
Laennecia schiedeana image

Annuals, 10-50(-100) cm. Leaf blades: bases ± clasping, faces usually sparsely and finely tomentose (hairs coarse, erect, multicellular) and stipitate- or sessile-glandular; proximal spatulate to oblong, 20-50+ × 5-15 mm, usually entire, sometimes 2-6-lobed or -toothed distally; distal narrowly oblong to linear, 10-20 × 1-5 mm, mostly entire. Heads borne in (narrowly cylindric) racemiform-paniculiform arrays (proximal in axils of distal leaves). Involucres 4-6 mm. Receptacles 3-4 mm diam. Pistillate florets 60-100+; corollas: ± equaling or surpassing styles, laminae 0.5-1+ mm. Disc florets 5-8+. Cypselae reddish brown, 1-1.5 mm, glabrous or sparsely strigillose (hairs 0.05-0.1 mm), sometimes glandular near apices; pappi ± persistent, of 12-20 white to tawny bristles in 1 series, 3.5-4 mm. 2n = 18.

Flowering late summer-early fall. Sandy roadsides, stream banks, openings in pine forests; 2000-2900 m; Ariz., Colo., N.Mex.; Mexico.

FNA 2006, Wiggins 1964, Kearney and Peebles 1969

Duration: Annual

Nativity: Native

Lifeform: Forb/Herb

General: Annual herb; forming densely hairy basal rosette when young. Stems 10-100 cm tall; glandular or sticky hairs all over plant, hairs resembling spider web (arachnoid); taproot.

Leaves: Numerous leaves, almost all cauline and clasping and with an oblong shape, many of them irregularly toothed, especially near the base. Leaves become smaller and have fewer teeth toward the top of the stem.

Flowers: Heads often rather numerous in a long and narrow inflorescence; bracts of the involucre often greenish; numerous pistillate flowers; pistillate corollas have a definite short ligule about .5 mm long, which surpasses the style.

Fruits: Cypselae, 1-1.5 mm long, with a very short neck.

Ecology: Found in open woods and on disturbed ground from 6,500-9,000 ft (1981-2743 m); flowers September-October.

Notes: Toothed leaves, hairy herbage, small flower heads; L. coulteri is found in ditchbanks, dry stream-beds and disturbed sites in this range. Flowers are similar to L. schiedeana, but leaves have many coarse teeth. Herbage is sticky-glandular but not loosely hairy or resembling strands of spider web (as in L. schiedeana). Also pistillate corollas without a ligule.

Ethnobotany: Unknown

Etymology: Laennecia is named for Rene Theophile Hyancinthe Laennec (1781-1826), while schiedeana is of uncertain origin.

Synonyms: Conyza schiedeana, Erigeron schiedeanus, Leptilon integrifolium

Editor: SBuckley, 2010