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28. Funastrum E. Fournier, Ann. Sci. Nat., Bot., sér. 6. 14: 388. 1882.
Twinevine, milkweed vine [Latin funis, rope, and -astrum, incomplete resemblance or diminutive, alluding to twining of stem tips in F. angustissimum, a South American species]
Mark Fishbein
Philibertella Vail; Sarcostemma R. Brown subg. Ceramanthus Kunze
Vines, herbaceous or somewhat woody and corky at base, perennial; latex white. Stems twining, unarmed, variously pubescent or glabrous. Leaves persistent or caducous, opposite, petiolate or sessile; stipular colleters interpetiolar; laminar colleters present or absent. Inflorescences extra-axillary, umbelliform, pedunculate or subsessile. Flowers: calycine colleters absent or present; corolla cream, cream tinged with pink or rose, greenish cream, reddish green, green, reddish brown, brown, bronze, pink, purple, or yellow, rotate-campanulate to rotate or tubular, aestivation contort-dextrorse; corolline corona absent; androecium and gynoecium united into a gynostegium adnate to corolla tube; gynostegial corona in 2 parts, one a raised, fleshy ring at insertion of staminal column on corolla, the other a whorl of 5 inflated segments on staminal column; anthers adnate to style, locules 2; pollen in each theca massed into a rigid, vertically oriented pollinium, pollinia lacrimiform, joined from adjacent anthers by translators to a common corpusculum and together forming a pollinarium. Fruits follicles, solitary or, less commonly, paired, pendulous, green to brown, lance-ovoid to fusiform, smooth, variously pubescent. Seeds winged, lanceolate to ovate, flattened, comose, not arillate.
Species ca. 18 (7 in the flora): s United States, Mexico, West Indies, Central America, South America.
R. E. Woodson Jr. (1941) and R. W. Holm (1950) treated the species of Funastrum as congeneric with those of Sarcostemma due to the remarkable similarity in the two-part coronas. The polyphyly of this concept was demonstrated by S. Liede and A. Täuber (2000). Subsequently, Sarcostemma in the narrow sense was synonymized with Cynanchum based on the phylogenetic results of Liede and Täuber (2002). Funastrum is endemic to the Americas, where the genus is recognized readily by its distinctive corona. The only discordant element in the current circumscription is F. utahense, which lacks a corona, but bears vegetative similarities to other species of the genus. The species of Funastrum are a common element of arid grasslands, coastlines, and riparian corridors in desert and scrub vegetation in subtropical North America. Several species reach their northern limits in the flora region, notably in the southwestern United States, and only F. utahense is endemic to the flora region.
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| 1 |
Leaf blades filiform, less than 0.02 cm wide; corollas tubular, yellow, lobes incurved; coronas absent |
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7 Funastrum utahense |
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Leaf blades linear or elliptic to lanceolate, ovate, deltate, or oval, usually greater than or equal to 0.02 cm wide; corollas rotate to rotate-campanulate, cream or shades of pink, purple, red, green, or brown, lobes spreading to ascending; coronas consisting of a ring and discrete lobes. |
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(2) |
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| 2 (1) |
Stems, leaves, peduncles, and pedicels hirtellous or hirsute (stems rarely pilose in F. torreyi). |
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(3) |
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Stems, leaves, peduncles, and pedicels glabrous, glabrate, pilose, or puberulent with curved trichomes. |
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(4) |
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| 3 (2) |
Leaf blades linear, rarely linear-lanceolate, 0.07–0.5 cm wide; pedicels 5–8 mm; corolla lobes 3–4 mm; follicles 4–5.5 × 0.3–0.5 cm; Ariz., Calif., Nev. |
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5 Funastrum hirtellum |
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Leaf blades deltate, lanceolate or ovate, 1.5–2.5 cm wide; pedicels 10–17 mm; corolla lobes 6–9 mm; follicles 8–9 × 1–1.5 cm; Tex. |
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6 Funastrum torreyi |
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| 4 (2) |
Leaf blade margins crispate, rarely plane; corollas shades of green, red, or brown, glabrous adaxially; corona lobes with medial constriction; follicles 10–13 cm; seeds 8–9 × 3–4 mm |
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2 Funastrum crispum |
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Leaf blade margins plane; corollas shades of cream, pink, or purple, minutely hispidulous to glabrate adaxially; corona lobes without constriction; follicles 5–9 cm; seeds 4–6 × 2–3 mm. |
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(5) |
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| 5 (4) |
Leaf blades elliptic to oval; corollas cream with red or maroon ring encircling corona, lobes 6–7 mm; follicles 5–6 cm |
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1 Funastrum clausum |
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Leaf blades ovate or lanceolate to linear; corollas shades of cream, pink, or purple, lacking red or maroon ring encircling corona, lobes 3–6 mm; follicles 6–9 cm. |
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(6) |
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| 6 (5) |
Leaf blades ovate to lanceolate, 0.7–4.5 cm wide, base commonly cordate, also sagittate or hastate; corollas most commonly cream or rose, often spotted or tipped with darker shades of rose; largely east of Pecos River |
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3 Funastrum cynanchoides |
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Leaf blades linear-lanceolate to linear, 0.1–1.5 cm wide, base commonly hastate or truncate, also sagittate or cordate; corollas most commonly shades of pink or purple or cream, spotted or tipped with pink or purple; largely west of Pecos River |
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4 Funastrum heterophyllum |
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Lower Taxa
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