Bulbs ovoid, 15-28 mm; stolons 1-3, common, mostly on 1-leaved, nonflowering plants. Leaves 8-23 cm; blade green, irregularly mottled, elliptic-lanceolate to ovate or elliptic, ± flat, glaucous, margins entire. Scape 10-18 cm. Inflorescences 1-flowered. Flowers: tepals yellow, sometimes tinged light to dark purple-red abaxially, sometimes with reddish dots adaxially, strongly reflexed at anthesis, lanceolate, 20-33 mm, inner with small auricles; stamens 9-15 mm; filaments yellow, lanceolate; anthers yellow, chestnut brown, or lavender; pollen yellow or brown; style deciduous or base forming small apiculum, greenish yellow, 5-11 mm, swollen distally or ± terete; stigma lobes erect or recurved, 1.5 mm. Capsules held erect or at least off ground at maturity, obovoid, 12-15 mm, apex rounded, truncate, or apiculate. 2n = 48. Erythronium americanum is a very common and widespread species, particularly in northeastern North America, becoming less frequent towards the southern and western limits of its range. Nonflowering plants far outnumber flowering ones in most populations because of their extensive stolon production. Plants with brown anthers have been called forma castaneum L. B. Smith.
Perennial herb with a bulb flowering stem 10 - 20 cm tall Leaves: one or two, born around middle of stem, appearing basal, 8 - 23 cm long, elliptic to egg-shaped to lance-shaped, flattened, irregularly mottled, with a waxy coating (glaucous). Flowers: yellow, often with reddish spots inside at the base, 1.5 - 5 cm long, with six distinct, lance-shaped tepals that eventually spread and curve backwards. Stamens six, 9 - 15 mm long. Filaments yellow. Anthers yellow, reddish brown, or lavender. Fruit: a 1 - 1.5 cm wide, egg-shaped capsule held more or less horizontally above the ground at maturity.
Similar species: Erythronium albidum is similar but has white flowers.
Flowering: April to mid-May
Habitat and ecology: Very local in the Chicago Region but frequent where it occurs. Found colonies in mesic woods. These colonies often contain many more one-leaved, non-flowering plants than the two-leaved flowering ones.
Occurence in the Chicago region: native
Etymology: Erythronium comes from the Greek word erythros, meaning red (certain European species have red flowers). Americanum means "of the Americas."
Extensively colonial; sterile corms numerous, producing a single lf and 2-several stolon-like offshoots; fertile corms few, 2-lvd; lvs mottled in life; scape stout, 1-2 dm; tep 1.5-5 cm, recurved-reflexed at anthesis, yellow, often spotted toward the base within or darker-colored outside, the pet with a small rounded auricle on each side 3-6 mm above the base; ovary and fr convex or truncate or apiculate, the fr commonly held above the ground ±horizontally; stigmas short, scarcely separate, terminating the clavate style; 2n=48. Moist woods; N.S. and w. Ont. to Minn., s. to Fla. and Ala., commoner eastward. Apr., May.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.