Oenothera suffulta (A. Gray) W. L. Wagner & Hoch, honeysuckle gaura. Annual, taprooted, 1–stemmed at base, unbranched or with several ascending to suberect branches in canopy, 25— 85+ cm tall; shoots with short–lived basal leaves and numerous cauline leaves, velveteen with short–villous and villous hairs.
Stems cylindric, to 3.5 mm diameter, tough, often aging reddish, villous with hairs to 2.5 mm long.
Leaves helically alternate, simple, short–petiolate, without stipules; petiole channeled or hemi–cylindric, to 2.5 mm long, white, short–villous on lower side; blade lanceolate or narrowly lanceolate to elliptic, narrowly oblong, or narrowly oblanceolate, 10—95 × < 2—23 mm, tapered to long–tapered at base, entire or subentire to low–dentate and wavy on margins, acuminate to acute with callus point at tip, pinnately veined with either midrib or with principal veins raised on lower surface, upper surface glabrate, lower surface and margins short–villous with upward–curved hairs.
Inflorescence spike, terminal, many–flowered, flowers helically alternate, in bud closely spaced, crowded, and overlapping, several open each day, bracteate, essentially glabrous; peduncle stemlike; bractlet subtending flower abscised at anthesis from persistent, cuplike base, base 0.5 mm long, upper portion cupped–obovate, 7.5—8 × 3 mm, white at base then rose, ± crimson above midpoint, short–ciliate at tip.
Flower bisexual, radial, 12—19 mm across; hypanthium ± cylindric but at base greenish portion slightly bowed, ca. 7 × 1 mm, 16–veined with 4 principal veins, basal portion 2 mm long, thick–walled, enclosing nectary, nectaries = 4 green ridges, upper portion pale greenish, outer surface glabrous, inner surface densely white villous–pilose; sepals 4, arising from rim of hypanthium, free (separating easily and completed), recurved, 10—15 × 1.5—1.8 mm, pale greenish with reddish stripe, 3–veined at base, acute at top, glabrous; petals 4, arising from rim of hypanthium, obovate, 9—15 × 3.5—5 mm, white, narrow at base, wavy on margins, rounded at tip; stamens 8 in 1 set, 4 opposite narrow bases of petals, 4 opposite midpoint of sepals, free, arising from rim of hypanthium, exserted; filaments ascending, 5—5.5 mm long, white, glabrous, with appendage at base, the appendage recurved toward orifice, narrowly tongue–shaped, 0.8 × 0.4 mm, colorless; anthers dorsifixed, dithecal, linear, 4.7—5.8 mm long, crimson, longitudinally dehiscent; pollen flat triangular, light cream–colored, held in a mass by minute threads (viscin threads); pistil 1, short–stalked; ovary inferior, 4–sided, ca. 5 × 1 mm, green, glabrous, 4–chambered, each chamber with 1 pendulous ovule, having membranous septum between chambers becoming 1–chambered in fruit; style exserted above anthers, cylindric, in range 12 mm long white to rose at top, glabrous at base then short–villous to 4 mm from base and glabrous above, at top with 4 yellowish, reflexed stigma lobes 2 mm long.
Fruit nutlike, indehiscent capsule, (1—)4–seeded, before drying 4–sided ovate spindle–shaped, 6—7 × 4—6 mm, with 4 major fleshy lobes alternating with 4 minor ridges becoming furrows at narrow, truncate tip, glabrous; endocarp 4–winged, extremely hard, white; stalk mostly < 1 mm long.
Seed ovoid or angular, 2—2.2 × 1.2—1.5 mm.
A. C. Gibson