Petunia parviflora Juss. (syn. Calibrachoa parviflora), wild petunia. Annual, taprooted, several–stemmed at base, principal branches tufted with unexpanded axillary shoots at many nodes, prostrate (decumbent), in range to 4 cm tall; with only cauline leaves, shoots densely glandular–pubescent, the hairs with bulbous bases and tannish heads, not ill–smelling.
Stems cylindric, to 1 mm diameter, internodes 3—10+ mm long, densely glandular–pubescent.
Leaves helically alternate (lower cauline leaves) and subopposite (upper cauline leaves + flower), simple, petiolate on lower stem and ± sessile on upper stem, without stipules; petiole channeled, to 1.5 mm long, < blade; blade oblanceolate to spatulate (lower cauline leaves), in range 4—10 × 1.2—3 mm, tapered at base, entire, rounded at tip, midrib only visible on lower surface, appearing bladderlike (vesicular) due to bulbous bases of glandular hairs.
Inflorescence leafy racemelike terminal shoots (flowers solitary), with a flower at node but not visually axillary to “leaf,” at same node with truly axillary new shoot from other leaf at approximately same level, bracteate, densely glandular–pubescent; bractlet leaflike, positioned to the side of pedicel; pedicel ± 0.7 mm long increasing 2× in fruit, appearing bladderlike (vesicular) where tops of glandular hairs missing.
Flower bisexual, radial, ca. 2 mm across; calyx 5–lobed, 7—8 mm long, persistent around developing fruit; tube cup–shaped, ca. 2 mm long, striped green alternating with membranous tissue and having green continue into lobes; lobes unequal, leaflike, oblanceolate, 3.5—6 mm long, rounded at tip, densely glandular–pubescent; corolla 5–lobed, trumpet–shaped (short–salverform), ca. 6 mm long, glandular–pubescent, in bud lobes twisted; tube–throat inversely narrowly conic, 4.8—5.2 mm long, at base 0.5 mm wide expanded during fruit enlargement and ca. 1.2 mm wide at orifice, tube pale green, throat pale violet, 5–veined with violet veins continuous into lobes; lobes initially pleated, broadly triangular and short, 0.5—0.6 × 0.8—1 mm, pale to light violet, with raised violet midvein on lower surface; stamens 5, fused to corolla tube above base at different heights, 4 stamens fused to corolla tube at same level, 1 short stamen fused at top of tube; filaments unequal, 1—2.7 mm long, light green, glabrous; anthers included, dorsifixed, dithecal, 0.5—0.6 mm long, yellow aging yellow orange, longitudinally dehiscent; pollen light yellow; nectary disc = 2 triangular swellings on base of ovary, 0.2 mm long, pale yellowish green; pistil 1; ovary superior, ovoid, ca. 1.3 × 0.8 mm, green, glabrous, 2–chambered, each chamber with many ovules attached to center; style ± 2.7 mm long, pale green; stigma included but slightly above level of anthers, capitate, ca. 0.3 mm wide, green, minutely papillate.
Fruit capsule, dehiscent by 2 ovate, terminal valves, many–seeded, ovoid, 4.5—5 mm long, tannish brown; calyx lobes remaining green after fruit dehiscence.
Seed ovoid–oblong to spheric, ± 0.5 mm long, light brown with frosted highlights, with low, netlike ridges forming pits.
A. C. Gibson & B. A. Prigge