Matelea hirtelliflora
Syst. Bot. 41: 781, figs. 1–3. 2016.
Vines, herbaceous. Stems 1(–5), twining, 50–200 cm, hirsute with eglandular and inconspicuous glandular trichomes. Leaves with 2 colleters on each side of petiole; petiole 2–7 cm, hirsute with eglandular and inconspicuous glandular trichomes; blade ovate to oval, 7.5–17 × 3.5–12 cm, base shallowly to deeply cordate, with 2–4 laminar colleters, apex acute to acuminate, surfaces hirsute with eglandular and inconspicuous glandular trichomes. Inflorescences solitary, simple or compound umbelliform, extra-axillary, pedunculate, 1–20(–30)-flowered; peduncle 0.5–6 cm, hirsute with eglandular and inconspicuous glandular trichomes. Pedicels 6–13 mm, hirsute with eglandular and inconspicuous glandular trichomes. Flowers: calyx lobes spreading, elliptic to lanceolate, 2–2.8 mm, apex acute to acuminate, hirsute with eglandular and inconspicuous glandular trichomes; corolla pale maroon to green with a maroon tinge abaxially, purple to maroon (with a green tinge) adaxially, not reticulate, shallowly campanulate, tube 1.5–2 mm, lobes erect to spreading, slightly twisted, oblong to narrowly deltate, 3.2–7.5 mm, margins plane (recurved), minutely hirtellous to glabrate; corona united to column near base, of 5 united, fleshy segments, each with 2 lateral lobes at apex equaling or exceeding medial lobe, forming a ring exceeding style apex, adaxial appendages incurved, incumbent on anthers, maroon, 0.7–1 mm, 3–4 mm diam., glabrous; apical anther appendages bright white with yellow to green patch at base; style apex green, pentagonal, flat. Follicles not striate, lance-ovoid, 6–10 × 1.3–3 cm, apex acuminate, moderately muricate, minutely hirsute. Seeds brown, ovate, 6–7 × 5–6 mm, margins broadly winged, chalazal end entire, faces rugose; coma 3–4.2 cm.
Phenology: Flowering Apr–Jun; fruiting Jun–Aug.
Habitat: Deep sandy soils, valleys, lake shores, hill slopes, oak-hickory and oak woodlands, pine-oak forests, often appearing following fires.
Elevation: 80–200 m.
Discussion
Matelea hirtelliflora is nearly endemic to the Piney Woods of eastern Texas. There is photographic documentation of the species in extreme southwestern Arkansas (Miller County), but we have not seen specimens. The few historical collections of this species were typically identified as M. decipiens prior to the description of the new species. Distinctions from M. decipiens are described under that species. Development with consequent habitat loss in the restricted range of M. hirtelliflora is cause for conservation concern.
Selected References
None.