Vascular Plants of Williamson County

Allium canadense var. fraseri [Alliaceae/Liliaceae]
fraser wild onion

Allium canadense L. var. fraseri Owney, fraser wild onion. Perennial herb, geophytic, bulb–bearing, rosetted, fibrous–rooted, scapose, inflorescence to 40 cm tall; shoot from bulb with 2—6 basal leaves with white sheath belowground, glabrous, when crushed with odor like onion (Allium); bulb to 60 mm deep, ovoid, at maturity 12—20 × 10—20 mm, outer coats brown and several persisting as a fibrous reticulum, lacking bulblets (bulbils) on inflorescence and also without basal bulbils; adventitious roots from base (stem) of bulb.

Leaves

Leaves helically alternate, simple with sheath; sheath closed from bulb upward to ground level, white; blade flattened on upper side to crescent–shaped in ×–section, 65—280 × 3—6.3 mm, < leaves, minutely bumpy on margins, acuminate at tip, parallel–veined, midrib not evident.

Inflorescence

Inflorescence umbel–like, hemispheroid, ca. 40 mm across, 20—30+–flowered, bracteate, glabrous; peduncle ascending to erect, cylindric, 1.7—3 mm diameter, green, glabrous; bract at top of peduncle enclosing flower buds, closed, having 3 prominent veins and splitting downward with 3 tail–like tips aging reflexed, membranous drying scarious and papery, 12—16 mm long, parallel–veined; bractlet subtending pedicel (except outer pedicels), membranous, slender, to 7.5 mm long; pedicels radiating, mostly 13—21 × ± 0.5 mm.

Flower

Flower bisexual, radial, 10—12 mm across; tepals 6 in 2 whorls, ± monomorphic, spreading, narrowly ovate to elliptic, 5.5—7 × 1.3—3.1 mm alternating wide and narrow widths, outer tepals acute and inner tepals obtuse to rounded at tip and narrower than outer whorl, white often with a faint green midstripe to midpoint on lower surface; stamens 6 in 2 close whorls, fused to bases of tepals and to each other; filaments erect, tapered to base, 3.1—4.6 × 0.4—0.5 mm, fused to 0.5 mm at flaring base, of inner whorl slightly wider and opposite inner whorl tepals, white; anthers versatile–dorsifixed or dorsifixed, dithecal, 1.2—1.7 mm long, white to cream–colored or pale yellow (rose), longitudinally dehiscent; pollen white to pale yellow; pistil 1, 4—5 mm long; ovary superior, lanceoloid to oblate conspicuously 3–lobed and lacking crests, 1.7—2.8 × 0.4 mm, white, glabrous, 3–chambered, each chamber with 2 ovule; nectaries = patches on ovary wall opposite inner tepals, producing nectar trapped at base of fused filament; style erect in center of ovary depression, tapered to tip, white, lacking crests, minutely 3–lobed at tip.

Fruit

Fruit capsule, loculicidal, 3–seeded, conspicuously 3–lobed, ca. 3 mm across, pale green (immature) drying tannish.

Seed

Seed strongly wedged–shaped, ca. 1.5 × 1.5 mm, glossy black, round on back and top and flattish on 2 sides.

A. C. Gibson