Diaperia verna (Raf.) Morefield var. verna, spring rabbit–tobacco, many–stem rabbit–tobacco. Annual, taprooted, several—many–stemmed at base, with ascending branches, in range 2—18 cm tall; monoecious; shoots leafy throughout, with densely white–woolly stems and inflorescence arrays, hairs less dense on foliage, not glandular, not aromatic. Stems: cylindric, to 1.5 mm diameter at base, tough, internodes to 5 mm long, without ridges decurrent from blades, glossy green beneath dense wool having long hairs oriented longitudinally.
Leaves helically alternate, simple, sessile, without stipules; blade oblong to oblanceolate, < 6—17 × 2—4.5 mm, slightly clasping at base, entire and often wavy on margins, broadly acute to obtuse at tip, only midrib visible raised on lower surface, cobwebby–woolly and surfaces equally hairy light green.
Inflorescence heads, terminal, solitary or several(—10+) in compact, hemispheric mound to 8 mm across, hidden by thick wool (lanuginous) until flowering heads become partially exserted to 2 mm, central flowers appearing as pits in the wool and in fruit styles slightly elevated above wool, head disciform, 2.5—3 mm across, with 13+ pistillate peripheral flowers lacking pappus (epappose), 3—4(—5) functionally staminate central flowers, sessile, subtended by bracts (capitular leaves), bracteate, densely white–woolly; capitular leaves like cauline leaves, mostly curved over array and often somewhat inrolled to the lower side, typically not exceeding height of exserted heads; involucre hidden in thick wool, phyllaries 4—6, subequal, membranous aging scarious, elliptic, ca. 2 × 1 mm, colorless or with green along midline, entire, rounded or shallowly notched at tip, with some long, loosely intertwined and crooked woolly hairs arising on green tissue above midpoint; receptacle subspheroid, having bractlets (paleae) subtending all flowers, never folded or keeled; paleae of pistillate peripheral flowers resembling phyllaries, ± erect, elliptic to narrowly obovate, ca. 2 mm long, slightly to strongly cupped behind pistillate flower, woolly above midpoint; paleae of staminate central flowers ascending to spreading, narrowly obovate–spatulate, slightly > pistillate paleae, with greater green area with greater wool and more narrow membranous margins.
Pistillate flower radial, 0.2 mm across; calyx (pappus) absent; corolla minutely 4–toothed, tubular, ca. 1.5 × 0.1 mm, mostly whitish but tinged purplish red at top, each tooth with stalked glands; stamens absent; pistil 1, ± 2 mm long; ovary inferior, narrowly ellipsoid and straight, 0.5—0.6 × 0.2 mm, white, 1–chambered with 1 ovule; style exserted, threadlike, ca. 2 mm long, 2–branched, the branches spreading and arching, ca. 0.3 mm long, white, stigmatic with tips aging reddish.
Staminate flower radial, appearing bisexual; calyx (pappus) absent; corolla minutely 4–lobed, tubular gradually expanding, ± 1.5 mm long, white, tube < 0.5 mm long and indistinct from throat, throat with somewhat flat sides, upper portion expanded around anthers; lobes acute, ca. 0.2 mm long, tinged reddish at tips; stamens 4, fused to corolla tube ca. 0.5 mm above base; filaments white, 0.7—0.6 mm long; anthers fused into cylinder surrounding style, basifixed, dorsifixed, ± 0.5 mm long, golden yellow, with short tails at base and sterile appendage at tip, longitudinally dehiscent; pollen golden yellow; pistil 1, included, ca. 1.7 mm long; ovary inferior, wedge–shaped and 4–sided, ca. 0.4 mm long, greenish, presumably 1–chambered but without ovule; style 1.2—1.4 mm long, white to midpoint and golden yellow to tip, with swelling at base.
Fruits cypselae of only pistillate flowers, without pappus, narrowly obovoid (ellipsoid), 0.7—0.9 × 0.3 mm, white aging light brown, beaded with raised cells in vertical lines; with persistent corolla and styles.
A. C. Gibson