Symphyotrichum ericoides (L.) G. L. Nesom var. ericoides, white heath aster. Perennial herb, ± clumped, rhizomatous, fibrous–rooted, appearing 1–stemmed at base arising belowground, upper cauline leaves often with tufted axillary shoots with future flowering branch, spreading to ascending or decumbent from woody rhizome, in range 10—30 cm tall; shoot with basal and mostly cauline leaves stiff and with point at tip, short–hairy and without glandular hairs; rhizome horizontal and shallow, when young whitish, aging to 6 mm diameter, scales 2/3–sheathing, appressed, deltate, ± 2 mm, sparsely short–hairy; adventitious roots mostly from lower side of rhizome.
Stems cylindric initially slender (< 1 mm diameter) becoming woody to 3 mm diameter, green and short–strigose with upward–pointing hairs aging with brown and gray periderm
Leaves helically alternate, simple, ssssile, without stipules; blades of basal leaves oblanceolate–linear, to 20 × 4 mm, of cauline leaves ± linear to narrowly lanceolate, 2—10+ × 0.7—1.4 mm, long–tapered and 1–veined or 3–veined from base, entire or short–ciliate on margins, acute to obtuse often with short hard, spinelike whitish point at tip, the tip often arching with point heading downward, in range sparsely short–strigose to glabrate.
Inflorescence head in terminal, paniclelike arrays, head radiate, 8—11 mm across, in range with mostly 14—16 ray flowers and 9—12 disc flowers, bracteate; peduncle having to 6 bracts along axis, bract oblong and half–cylindric, 1.3—3 mm long, somewhat fleshy, short–ciliate, with short spine at tip; involucre initially bell–shaped, 4—5 × 2.5—3 mm, phyllaries unequal, whitish below midpoint, short–ciliate, with short point at tip, outer phyllaries spreading, oblong–elliptic and half–cylindric, ca. 2 mm long, green above midpoint, middle phyllaries ca. 10, oblong, 1.9—3.5 mm long, whitish with green midvein and approaching tip, inner phyllaries 5—7, membranous, flat, 3.6—4.1 mm long; receptacle slightly domed, with crownlike teeth surrounding each ovary, 0.3—0.4 mm long, colorless.
Ray flower pistillate, bilateral, ca. 1 mm across; calyx (pappus) capillary bristles, ca. 3 mm long, white; corolla minutely (2—)3–toothed, ca. 5 mm long; tube cylindric ca. 1.5 mm long, white; limb spreading, elliptic, ± 3.5 × 0.7—1.1 mm, white (purplish); stamens absent; pistil 1, ca. 4 mm long; ovary inferior, funnel–shaped, ca. 0.8 × 0.35 mm, white, covered with ascending short hairs, 1–chambered with 1 ovule; style ca. 3 mm long, white, 2–branched, the branches ca. 1.1 mm long
Disc flower bisexual, radial, < 1 mm across; calyx (pappus) ca. 40 capillary bristles, subequal, (2—)3—3.5 mm long, white; corolla 5–lobed, 3—3.7 mm long; tube ± cylindric, 0.8—1.2 mm long, greenish to colorless; throat narrowly funnel–shaped, 1.8—2 mm long, colorless to yellowish, lobes acute, 0.4—0.6 mm long, colorless with light yellow veins and margins; stamens 5, fused at top of corolla tube; filaments 0.8—0.9 mm long, colorless; anthers fused in cylinder surrounding style, basifixed, dithecal, ca. 1.3 mm long including acute appendage at tip, light yellow, longitudinally dehiscent; pollen light yellow; pistil 1, 4 mm long; ovary inferior, funnel–shaped, ca. 0.8 × 0.35 mm, white, covered with ascending short hairs, 1–chambered with 1 ovule; style 3.7—3.9 mm long, 2–branched, mostly white below branches, the branches appressed, slender, ca. 0.9 mm long, yellowish.
Fruits cypselae (achenes), cylindric, ca. 0.8 × 0.3 mm, pale brown and 10–striped; pappus subequal, 3—3.5 mm long, tawny.
A. C. Gibson