Warnockia scutellarioides (Engelm. & A. Gray) M. W. Turner, prairie brazoria, rattlesnake flower. Annual, taprooted, not rosetted, 1(—3)–stemmed at base, with opposite decussate pairs of ascending to spreading lateral branches from successive nodes along principal axis, erect, with inflorescences in range 7—35 cm tall; shoots with only paired cauline leaves, glabrous and not aromatic.
Stems ± 4–sided and 4–ridged, to 3 mm diameter (at ± persistent cotyledon), 2 sides low–convex to flattish (descending from leaf midrib) and 2 sides 2–ridged (descending from paired blade edges), green but often dark red–purple at base of plant, ridges often pinkish and with inconspicuous stalked glandular hairs.
Leaves opposite decussate, simple, sessile, without stipules; blade oblong, 11—50+ × 4—11+ mm, lobed and nearly clasping to long–tapered at base, entire to subentire and wavy or with small or inconspicuous teeth approaching tip, pinnately veined with principal veins sunken on upper surface and raised on lower surface.
Inflorescence raceme, terminal, erect, and relatively dense, having 10—20+ pairs of opposite decussate flowers, bracteate, short–hirsute and with stalked glandular hairs; peduncle 4–sided, to 25 mm long, lacking ledges, sides channeled; rachis 4–sided and channeled; bractlet subtending pedicel, at base of raceme lanceolate and to 11 × 4 mm, mostly appearing petiolate and obovate, 4 × 1.5—2 mm, ± reflexed from petiolelike, entire or with several teeth on margins approaching tip (large bractlets), with point at tip, short–hirsute and with stalked glandular hairs; pedicel ascending, compressed top–to–bottom, 1—2 mm long increasing in fruit, short–hirsute and with stalked glandular hairs.
Flower bisexual, bilateral, 8—9 mm across; calyx 2–lipped, 5–lobed, ca. 7 mm long, green with translucent dashes and dots (= crystal inclusions), short–hirsute on outer surface, glabrous on inner surface; tube funnel–shaped, to 3.5 mm long, 10–veined raised at least above midpoint to lobes and sinuses; upper lip 3–lobed, lobes from base of lip, ovate, lateral lobes 2.5 × 2 mm with short point at tip, central lobe 2 × 2.5 mm without a short point at tip, having scattered glandular hairs on outer surface; corolla 2–lipped, 4–lobed, 12—14 mm long; tube somewhat cylindric, ca. 4 × 1.5 mm, white but above midpoint blushed pale pink–purple, enlarged around ovary, with short radiating hairs above midpoint pale pink–purple; throat conspicuously expanded and bell–shaped, ± 3.5 × 3.5 mm, light pink–purple with colored short hairs on outer surface, inner lateral and top surfaces with light pink–purple pattern but floor mostly white, outer surface papillate and with some glandular hairs; upper limb not lobed, rounded with margins somewhat curved downward, 4.5—5 mm, pink–purple; lower lip 3–lobed, angled downward, 5—6 mm long, lateral lobes obovate, ca. 4 × 3 mm, solid pink–purple, subentire on margins, central lobe with 2 subtle sublobes and a tooth in center, 1 mm > lateral lobes, pink–purple at margins but mostly white with 2 dotted lines outside floor of throat, outer surface of upper lip with some nonglandular and glandular hairs; stamens 4 in 2 pairs, positioned within upper corolla lip, long stamens arising laterally at top of corolla tube, shorter stamens arising in lower throat on upper side; filaments cylindric, ca. 6 mm long (long stamens) and 4 mm long (shorter stamens), white but blotched pale pink–purple, short–hairy in middle portion; anthers dorsifixed, dithecal, 0.7 × 0.9 mm, red–purple with purplish pink connective, longitudinally dehiscent; pollen yellowish; nectary disc crownlike arising beneath ovary, on upper side to below midpoint on ovary, broad, and greenish, on lower side nearly to top of ovary, broadly triangular, and whitish, nectar–producing; pistil 1; ovary superior, strongly 4 lobed from base, lobes obovoid rounded at top, 0.7—0.8 mm long, yellow–green, 2–chambered, each lobe with 1 ovule; style attached to ovary base at center of ovary lobes (gynobasic), positioned within upper corolla lip and not exserted beyond corolla, ± 9.5 mm long, white, glabrous, 2–branched, the branches stigmatic, at level of upper anthers, unequal, slightly recurved, 0.9—1.2 mm long with the shorter branch on top, light pink–purple aging darker and coiled.
Fruits nutlets (1—)4, 3–sided and wider above midpoint, 1.3—1.5 × 1.3—1.4 mm, brown, minutely textured with domed cells; calyx lower lip pressed upward against upper lip concealing nutlets.
A. C. Gibson