Matelea biflora
Matelea producta
star milkvine, two flower matelea, two-flower milkvine
Texas milkvine
4–10, decumbent, often branched near base, 7–40 cm, hirsute with long eglandular and minute glandular trichomes.
1–5, twining (at least at stem tips), 30–200 cm, short-hirsute with spreading to retrorse eglandular and minute glandular trichomes.
1 or 2 colleters on each side of petiole;
petiole 0.5–2.5 cm, hirsute with long eglandular and minute glandular trichomes;
blade ovate to deltate, 0.8–5 × 0.6–3.2 cm, base shallowly to deeply cordate, with 0–2 laminar colleters, apex acute (rounded), surfaces hirsute with long eglandular and minute glandular trichomes, especially so on veins abaxially.
with 1 or 2 colleters on each side of petiole;
petiole 0.5–3 cm, short-hirsute with eglandular and minute glandular trichomes;
blade ovate to lanceolate, 2.5–8 × 1–5.5 cm, base deeply cordate, with 2–4 laminar colleters, apex long-acuminate, surfaces densely hirsute, eglandular.
solitary, umbelliform, extra-axillary, sessile or subsessile, 1–2-flowered.
solitary (rarely paired), simple umbelliform or somewhat racemiform, extra-axillary, pedunculate, 2–8-flowered;
peduncle 0.6–1.7 cm, short-hirsute with eglandular and minute glandular trichomes.
3–11 mm, hirsute with long eglandular and minute glandular trichomes.
4–9 mm, short-hirsute with eglandular and minute glandular trichomes.
calyx lobes spreading, oval to ovate, 1.8–2.5 mm, apex rounded or acute, hirsute with long eglandular and minute glandular trichomes;
corolla maroon to dark brown, not reticulate, rotate-campanulate, tube 1–1.5 mm, lobes spreading, ovate to narrowly deltate to spatulate, 3–6 mm, margins usually reflexed, pilose to hirsute adaxially;
corona united to corolla and column near base, composed of 5 united segments forming a ring at base, each with an adaxial incurved appendage arching above or incumbent on anthers, equaling or exceeding style apex, maroon to dark brown, 1–1.5 mm, glabrous;
apical anther appendages white, maroon to brown at base, broadly deltoid;
style apex rounded, flat.
calyx lobes ascending, elliptic to lanceolate, 2–4 mm, apex acute, short-hirsute with eglandular and minute glandular trichomes;
corolla green to reddish abaxially, green to yellowish green with dark green reticulations (rarely brown) adaxially and a thin red to purple ring at top of throat, tubular-campanulate, tube 3.5–8 mm, lobes spreading, 5–7 mm, hirtellous abaxially, glabrous adaxially;
corona concealed in throat, a ring with 5 lobes incumbent on backs of anthers, green to pinkish or lavender, 1–1.5 mm, glabrous;
apical anther appendages greenish or yellowish cream, deltoid;
style apex green to yellowish green, pentagonal, flat.
tan to light brown, oval to nearly orbicular or ovate, 8–11 × 7–10 mm, margins broadly winged, chalazal end erose, faces minutely rugose;
coma 2.5–4 cm.
tan, ovate, 6–8 × 4–5 mm, margins thickly winged, chalazal end minutely erose, faces smooth;
coma 2–3 cm.
not striate, ellipsoid to ovoid, 4.5–8.5 × 1.8–3.5 cm, apex acute, densely muricate (more than 1 protrusion per cm of length), villous to hirsute with long eglandular and minute glandular trichomes.
gray-striate, fusiform to ellipsoid, 7–10 × 1.5–2.5 cm, apex acuminate, smooth, glabrous.
, herbaceous (rarely suffrutescent without corky bark).
Matelea biflora
Matelea producta
Matelea biflora is occasionally found in grasslands and savannas of the southern Great Plains. It is most common on and around the Edwards Plateau of central Texas, where it occurs in grass-dominated habitats including disturbed areas. The range extends mostly northward and westward of that region to central Oklahoma and extreme eastern New Mexico (Lea County), where the species is much less common. Its conservation status in New Mexico merits evaluation. The plants are covered in short, glandular hairs and are malodorous when touched. The flowers occur most often in pairs, hence the common name two-flowered milkvine.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Matelea producta occurs in the flora area along a narrow arc from the Grand Canyon near Lake Mead in Arizona to the Trans-Pecos region of Texas and at scattered locations in northern New Mexico. Its tubular-campanulate green corolla is unlike that of any other milkweed vine in its range, except the very similar M. texensis, which differs by densely hirtellous corollas. However, M. texensis is narrowly endemic to a small region south of Alpine, Texas, just beyond the range of M. producta. The species are as of yet not known to co-occur. Many Matelea species have corollas that range in color from green to shades of maroon or brown. The corollas of M. producta are almost invariably green adaxially; however, a specimen gathered from the Davis Mountains of western Texas (Rintz 2006-1, SRSC) represents the only known occurrence of brown flowers in this species. Although milkweed vines in several genera are well known for ill-scented herbage, M. producta is particularly malodorous.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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