Large-flower milkweed

Anantherix connivens (Baldwin) Feay

Herbs. Stems 1, erect, unbranched (rarely branched), 25–90 cm, minutely puberulent with curved trichomes or pilose to glabrate, not glaucous, rhi­zomes absent. Leaves opposite, sessile or petiolate, with 1 or 2 stipular colleters on each side of petiole; petiole 0–1 mm, puberulent with curved trichomes to glabrate; blade narrowly elliptic to linear or oblanceolate, 2.5–8 × 0.3–2.5 cm, chartaceous, base cuneate, margins entire, apex acute to rounded, mucronate, venation brochidodromous, surfaces sparsely pilose to glabrate, midvein puberulent with curved trichomes to glabrate, margins ciliate, 0–6 laminar colleters. Inflorescences terminal, sometimes branched, and extra-axillary at upper nodes, pedunculate, 4–8-flowered; peduncle 0.9–6 cm, densely puberulent with curved trichomes, with 1 caducous bract at the base of each pedicel. Pedicels 10–20 mm, densely puberulent with curved trichomes. Flowers spreading to pendent; calyx lobes lanceolate, 4–6 mm, apex acute, sparsely pilosulous; corollas green, sometimes tinged brown at apex, lobes reflexed with spreading tips, elliptic, 10–13 mm, apex acute to obtuse, sometimes emarginate, glabrous; gynostegial column 1–1.5 mm; fused anthers green, obconic, 3–3.5 mm, wings narrowly right-triangular, distended at base, closed, apical appendages oval; corona segments cream to pale green, stipitate, clavate, incurved, 8–10 mm, greatly exceeding style apex, apex rounded, glabrous, internal appendage a hidden crest, glabrous, apices of the 5 segments sometimes connivent; style apex depressed, green. Follicles erect on upcurved pedicels, fusi­form, 11.5–15 × 0.5–1.4 cm, apex long-attenuate, smooth, minutely pilosulous. Seeds ovate, 7–9 × 5–6 mm, margin winged, faces minutely and sparsely rugu­lose; coma 3–3.5 cm.

Flowering May–Aug(–Sep); fruiting Jul–Sep(–Nov). Flats, sandy soils, pine flatwoods and barrens, often recently burned, wet meadows, marshes, bogs, swamps; 0–200 m; Ala., Fla., Ga., S.C.

Asclepias connivens is a singular species—the large, incurved, clavate corona segments are unlike any others in the genus. With wide leaves and large flowers, A. connivens is more conspicuous than most co-occurring milkweeds, such as A. cinerea, A. feayi, A. pedicellata, and A. viridula. It prefers wet soils and often occurs at the same sites as A. viridula and the red-orange-flowered A. lanceolata. Asclepias connivens barely enters South Carolina in Jasper and Beaufort counties and is considered rare and to be of conservation concern in that state. It has been reported from Mississippi, but there are no specimens from that state, and occurrence there seems unlikely, as A. connivens has not been documented from southwestern Alabama either. It would be interesting to discover what pollinates the large and unusual flower of A. connivens; however, there appear to be no reports of flower visitors to this species.