1. Cuphea viscosissima Jacq. (clammy cuphea, blue waxweed)

C. petiolata (L.) Koehne, an illegitimate name

Pl. 448 k–m; Map 2033

Plants terrestrial, annual, fibrous-rooted, not rooting at the nodes, not producing offsets at the base. Stems 10–60 cm long, erect or strongly ascending, not wandlike, circular in cross-section, usually much-branched throughout, the branches spreading to ascending, not rooting at the tip, densely pubescent with longer, spreading, sticky, gland-tipped hairs and shorter, spreading, nonglandular hairs, purplish-tinged above the midpoint. Leaves opposite, petiolate, the petiole 3–15 mm long. Leaf blades 2.0–5.5 cm long, 5–20 mm wide, narrowly lanceolate to ovate, narrowed to a bluntly or more commonly sharply pointed tip, rounded or angled to short-tapered at the base, the surfaces sparsely to moderately pubescent with short, nonglandular hairs, sometimes somewhat roughened to the touch, more densely hairy along the main veins. Inflorescences of solitary, axillary flowers, these sometimes appearing grouped into open, leafy racemes, the flower stalks 1–5 mm long. Flowers zygomorphic, the hypanthium much longer than wide, cylindrical to narrowly urn-shaped, with a rounded pouch or spur at the base on 1 side, oblique at the tip, the hypanthium plus sepals 8–12 mm long, with 12 longitudinal ridges, dark purple toward the tip, yellowish, pinkish, or green toward the base, the outer surface densely pubescent with spreading, sticky, dark-colored, gland-tipped hairs, the inner surface with short, nonglandular hairs, splitting longitudinally along the upper side as the fruit dehisces. Sepals 6, the upper 1 larger than the other 5, triangular to broadly ovate-triangular, the appendages inconspicuous, much shorter than the sepals, triangular. Petals 6, 3–6 mm long, the upper 2 longer than the other 4, purple, not persistent at fruiting. Stamens 11, those of different flowers with filaments of similar lengths, but the filaments alternately shorter and longer within each flower, the anthers slightly exserted, purple. Pistils with a curved nectary along the base of the upper side, the ovary incompletely 2-locular, usually appearing 1-locular at fruiting, the style 3–5 mm long, not or only slightly exserted. Fruits 5–8 mm in diameter, globose to ovoid capsules, dehiscing longitudinally along the upper side, the outer wall smooth, membranous to papery. Seeds 7–10, 2–3 mm in diameter, flattened, more or less circular in outline, the surface minutely tuberculate, dark brown. 2n=12. July–October.

Scattered, mostly south of the Missouri River, but apparently absent from most of the Mississippi Lowlands Division (eastern U.S. west to Nebraska and Oklahoma; Canada). Glades, tops of bluffs, savannas, swales in sand prairies, openings of dry upland forests, and banks of streams and spring branches; also old fields, ditches, quarries, railroads, roadsides, and open disturbed areas.

Traditionally, this species was called C. petiolata (L.) Koehne, but that name is a homonym of the older C. petiolata Pohl ex Koehne, a different South American species (Graham, 1964).