Houstonia pusilla Schöpf, tiny bluets, star–violet, small bluet, innocence, southern bluet, angel eyes, quaker ladies. Annual, slender–taprooted, not rosetted, 1–stemmed at base, ± erect with ascending branches in canopy, < 10 cm tall; shoots with only cauline leaves at 2—5 nodes, glabrous.
Stems 4–sided and 4–ridged, < 1 mm diameter, with 2 ridges decurrent from each leaf (4 per node), weak, ridge edges sometimes vesicular and aging reddish.
Leaves opposite decussate, simple, petiolate and fused at node with stipules; stipules 2 per node, ± triangular, ca. 0.8 × 0.8 mm, nearly colorless, acuminate or 2–toothed at tip, with several orangish, conic glands on margins near petiole; petiole broadly channeled, < 1—5 mm long; blade ovate, 4—8 × 2—4.5 mm, tapered at base, entire, acute to obtuse at tip, inconspicuously veined with only the faint midrib visible, upper surface minutely bumpy, lower surface smooth.
Inflorescence
Flower bisexual ± radial, 7—9 mm across; calyx deeply 4–lobed, scarcely fused at base, green, glabrous; lobes suberect, somewhat unequal, triangular to narrowly ovate, 2.5—3 × 0.7—0.9 mm, pair on broader side wider, on edges with enlarged bases; corolla 4–lobed, trumpet–shaped, glabrous; tube flared at base, ca. 2 mm long, white with 4 greenish veins; throat ± cylindric with 4 faint ridges, initially ca. 2.5 mm long and exserted from calyx after anthesis, flaring upper portion cuplike, to 1 mm long, violet to bluish on outer surface, inner surface reddish purple with yellowish starlike pattern pointing to sinuses; lobes initially erect then spreading, ovate to broadly elliptic, 4—5 × 2—2.3 mm, light violet to bluish, upper throat and lobes minutely papillate, lower surface paler, veins inconspicuous; stamens 4, attached at top of corolla tube, included; filaments slender, to 0.4 mm long, pale green; anthers dorsifixed, dithecal, 0.5—0.6 mm long, light yellow, longitudinally dehiscent; pollen light yellow; pistil 1; ovary inferior, strongly 2–lobed with 4 shallow grooved and compressed side–to–side, ca. 0.5 × 1 mm, green, glabrous, 2–chambered each chamber with several ovules; style 0.6—0.7 mm long, 2–branched, lower portion nearly colorless and branches pale green, the branches ascending and at level of anthers, stigmas short papillate.
Fruit capsule, with 4 spreading, triangular calyx lobes, to 16–seeded, each half resembling a gecko head, ca. 2.5 × 4.5 × 2 mm.
Seed helmetlike, ca. 1 mm long.
A. C. Gibson