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Carolina or maroon Carolina milkvine, maroon Carolina milkvine

prairie milkvine

Habit Herbs.
Stems

1–2(–5), twining, 100–300 cm, hirsute with eglandular and inconspicuous glandular trichomes.

3–10, ascending to decumbent, often branched near base, 10–70 cm, hirsute with long eglandular and minute glandular trichomes.

Leaves

with 2 colleters on each side of petiole;

petiole 1–9 cm, hirsute with eglandular and inconspicuous glandular trichomes;

blade ovate to orbiculate, 3–20 × 1.5–18 cm, base shallowly to deeply cordate, with 2–4 laminar colleters, apex acute to acuminate, surfaces hirsute with eglandular and inconspicuous glandular trichomes.

with 1 or 2 colleters on each side of petiole;

petiole 0.5–1.3 cm, hirsute with long eglandular and minute glandular trichomes;

blade ovate to deltate (elliptic or orbiculate), 2.2–5.4 × 1–4.5 cm, base shallowly to deeply cordate, with 0–4 laminar colleters, apex acute to acuminate, surfaces hirsute with long eglandular and minute glandular trichomes, especially so on veins abaxially.

Inflorescences

solitary, simple or compound, umbelliform to racemiform, extra-axillary or terminal, pedunculate, 3–30(–40)-flowered;

peduncle 1–13 cm, hirsute with eglandular and inconspicuous glandular trichomes.

solitary, umbelliform, extra-axillary, some appearing terminal, pedunculate, 2–6-flowered;

peduncle 0–3 cm, hirsute with long eglandular and minute glandular trichomes.

Pedicels

3–30 mm, hirsute with eglandular and inconspicuous glandular trichomes.

3–5 mm, hirsute with long eglandular and minute glandular trichomes.

Flowers

calyx lobes spreading, ovate to elliptic to lanceolate, 1.5–4.5 mm, apex acute to acuminate, hirsute with eglandular and inconspicuous glandular trichomes;

corolla pale maroon to yellowish green tinged with maroon abaxially, dark maroon, dark brown, or dark purple (yellow and maroon or yellow with maroon tinge at base), with a cream to light rose (maroon) ring at base of corona adaxially, reticulate markings only apparent on yellow forms, rotate to campanulate, tube 1–2 mm, lobes spreading to erect or somewhat reflexed, sometimes twisted, oblong, 4–15 mm, margins plane (reflexed), minutely hirtellous abaxially, glabrous adaxially;

corona united to column near base, of 5 united, fleshy segments, each with 2 lateral lobes at apex exceeding the medial lobe, forming a sheath that equals or slightly exceeds style apex, adaxial appendages incurved, incumbent on anthers, sometimes concealed when corolla lobes erect, maroon (orange-yellow or green-yellow), 0.7–2 mm, 2–3 mm diam., glabrous;

apical anther appendages bright white with yellow to maroon patch at base, rhomboid;

style apex pink to maroon, pentagonal, flat.

calyx lobes spreading, elliptic (ovate), 2–3 mm, apex acute, hirsute with long eglandular and minute glandular trichomes;

corolla green to brown or maroon, not reticulate, rotate-campanulate, tube 0.9–1.2 mm, lobes spreading, planar, deltate to ovate, 2.5–4 mm, glabrous 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 incumbent on anthers, exceeded by style apex, green, yellow, or brown, 0.7–1 mm, fleshy, glabrous;

apical anther appendages white, maroon to brown at base, rounded-truncate;

style apex rounded-conic.

Seeds

brown, ovate (orbicular), 8–9 × 6–8 mm, margins broadly winged, chalazal end entire, faces rugose;

coma 2.5–3.5 cm.

tan to light brown, broadly ovate to nearly orbicular, 10–12 × 9–10 mm, margins broadly winged, chalazal end erose, faces minutely rugose;

coma 2.5–3.5 cm.

Vines

, herbaceous.

Follicles

not striate, lance-ovoid to nearly fusiform, 7–13 × 1–2.5 cm, apex acuminate, sparsely to moderately muricate, minutely hirsute.

not striate, ovoid to ellipsoid, 5–9.7 × 1.8–3.5 cm, apex acute, sparsely muricate (fewer than 1 protrusion per cm of length), hirsute.

Matelea carolinensis

Matelea cynanchoides

Phenology Flowering Apr–Jul(–Aug); fruiting Jun–Oct(–Nov). Flowering Apr–Sep; fruiting May–Oct.
Habitat Hill slopes, bluffs, ridges, flats, valleys, streamsides, ditches, rock outcrops, limestone, sandstone, gabbro, serpentine, sandy and loamy soils, talus, cedar glades, barrens, oak woods, oak-hickory, oak-pine, mixed-hardwood, pine-mixed hardwood, pine, and riparian forests, old fields, secondary woods, pine plantations. Sandy prai­ries, flood plains, stabilized dunes, hillsides, pastures, fields, savannas, pine-oak forests.
Elevation 0–700 m. (0–2300 ft.) 10–600 m. (0–2000 ft.)
Distribution
from FNA
AL; DC; DE; GA; KY; LA; MD; MS; NC; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; LA; OK; TX
[BONAP county map]
Discussion

Matelea carolinensis is a widespread and variable species that has long presented challenges in circumscription. The most widely distributed and common form has small, nearly rotate corollas with deltate to oval corolla lobes that are sometimes reflexed. However, Appalachian populations in the Carolinas may vary by having larger flowers with lobes that are much narrower and ascending. In the Appalachian region, there is a bewildering array of floral diversity including large and small corollas with ascending lobes and individual plants with lobes that are reflexed, spreading, and ascending, perhaps in part due to developmental changes. Plants from the Carolinas with large corollas and ascending lobes have been considered to be conspecific with those in the Ozark region treated here as M. decipiens since that species was first described by Alexander. These two population systems are strongly disjunct. Careful study of corona structure suggests that these populations are convergent in their narrow, campanulate corollas and that the Appalachian plants belong to the same species as the widespread populations with smaller, rotate corollas with which they intergrade. Further study using population genetics and other data types is needed to address conflicting treatments of these plants. As currently understood, M. carolinensis occurs almost entirely east of the Mississippi River with only a few isolated occurrences in Louisiana west of the river (for example, Thomas 13,124 [TENN] from Catahoula Parish). Conversely, M. decipiens occurs entirely west of the river. Matelea carolinensis has suffered habitat loss at the northern edge of its range. It is presumed to be extirpated in the District of Columbia and is uncommon and of conservation concern in Delaware, Kentucky, and Maryland. Reports from Pennsylvania and West Virginia have not been confirmed and probably represent misidentifications of M. obliqua.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Matelea cynanchoides occasionally occurs in sandy grasslands, savannas, and forests of the southern Great Plains. It is more abundant on the Gulf Coastal Plain of southeastern Texas in alluvial deposits overlying sandstone. The range extends eastward and northward to western Louisiana (Caddo Parish), extreme southwestern Arkansas (Miller County), and central Oklahoma, where the species is limited to deposits of deep sands. At the edge of its range, M. cynanchoides is considered to be of conservation concern in Arkansas and Louisiana. The plants are covered in short, glandular hairs and are malodorous when touched. Matelea cynanchoides is tolerant of disturbance, and resprouted, prostrate plants can be found on roadsides that are subject to regular mowing.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 14. FNA vol. 14.
Parent taxa Apocynaceae > Matelea Apocynaceae > Matelea
Sibling taxa
M. alabamensis, M. atrostellata, M. baldwyniana, M. biflora, M. brevicoronata, M. chihuahuensis, M. cynanchoides, M. decipiens, M. edwardsensis, M. flavidula, M. floridana, M. hirtelliflora, M. obliqua, M. parviflora, M. parvifolia, M. producta, M. pubiflora, M. radiata, M. reticulata, M. sagittifolia, M. texensis
M. alabamensis, M. atrostellata, M. baldwyniana, M. biflora, M. brevicoronata, M. carolinensis, M. chihuahuensis, M. decipiens, M. edwardsensis, M. flavidula, M. floridana, M. hirtelliflora, M. obliqua, M. parviflora, M. parvifolia, M. producta, M. pubiflora, M. radiata, M. reticulata, M. sagittifolia, M. texensis
Synonyms Cynanchum carolinense, Gonolobus carolinensis, Odontostephana carolinensis Gonolobus cynanchoides
Name authority (Jacquin) Woodson: Ann. Missouri Bot. Gard. 28: 228. (1941) (Engelmann & A. Gray) Woodson: Ann. Missouri Bot. Gard. 28: 228. (1941)
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