Plantago aristata Michx., bottlebrush plantain, bracted plantain, buckhorn. Annual, taprooted, rosetted, 1—several–stemmed at base, acaulous, scapose with < 12 inflorescences, in range to 37 cm tall; shoots with ascending basal leaves, finely long–pilose with hairs 5 mm long.
Stems at plant base where leaves attached.
Leaves helically alternate, simple, petiolate but indistinct and with sheathing base, without stipules; petiole sheathlike flat and 2× lower blade, parallel–veined and 5–veined with wide membranous margins, indistinct from blade; blade strap–shaped, < 80—170 × 2.5—14 mm, entire, acute at tip, parallel–veined with (3)5 principal veins and midrib raised slightly on lower surface, upper surface with scattered, inconspicuous glandular hairs, lower surface mostly pilose and with some scattered glandular hairs.
Inflorescence spike = plant height, terminal on scapelike peduncle axillary to basal leaf, 1—several(—11) per plant, densely many–flowered, flowers in whorls of 3, overlapping, flowers chasmogamous and mostly cleistogamous, bracteate, pilose; peduncle (scape) cylindric, < 2 mm diameter, pilose at base to short–strigose (appressed hairs < 0.5 mm long) above midpoint; rachis 6–angled, mostly concealed by flowers, internodes to 3 mm in fruit; bractlet subtending flower linear and conspicuous, 12—42 × 1—3 mm, >> flower, the lowest whorl having 1 of 3 the longer and the widest, basal 3—4 with membranous wings, upper surface glabrate, lower surface fine–hairy.
Flower bisexual, ± radial, 3.5—4 mm across; calyx deeply 4–lobed fused only at base, lobes overlapping, subequal, boat–shaped but not sharply keeled, ca. 1.5 mm long, scarious and herbaceous, the lower 2 lobes with green portion 0.8—1 mm wide, the upper 2 lobes with green portion 0.4—0.5 mm wide, green portion with soft hairs on outer (lower) surface, scarious margins short–hairy on outer surface; corolla 4–lobed, membranous, colorless; tube cylindric but conforming to shape of developing ovary, ca. 3 mm long (chasmogamous flower) or shorter (cleistogamous flower), green aging translucent white, with a narrow, 4–sided orifice; lobes spreading and later reflexed or erect (cleistogamous flowers), cupped–ovate, 1.5—2.2 mm long in a single flower (chasmogamous flower), the upper lobe the shortest and narrower and lower lobe the widest, cordate at base, broadly acute at tip; stamens 4, alternate with corolla lobes, fused to corolla tube below sinuses; filaments threadlike, 0.8—1 mm long, white; anthers dorsifixed, dithecal, 0.4 mm long including appendage at top, pale yellow, longitudinally dehiscent; pollen pale yellow to colorless; pistil 1, 2 mm long, included; ovary ovoid maturing elliptic, green, glabrous, 2–chambered, each chamber with 1 ovule attached to center; style erect, 1.1—1.3 mm long, white but green at base, conspicuously long–papillate.
Fruit capsule, dehiscent around fruit (circumscissile) 1 mm from base, 2–seeded, obovoid, in range (3—)4 × 2 mm, brownish.
Seed hemi–obovoid to hemi–ellipsoid, 2.5—3.3 mm long, reddish brown to brown, rounded on back, deeply concave on flat side,
A. C. Gibson