Funastrum crispum
| Funastrum crispum | |
|---|---|
 | |
| Funastrum crispum in bloom | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Embryophytes |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Apocynaceae |
| Genus: | Funastrum |
| Species: | F. crispum |
| Binomial name | |
| Funastrum crispum | |
| Synonyms | |
| |
Funastrum crispum, commonly known as the wavyleaf twinevine or wavy-leaf twinevine, is a species of flowering plant in the dogbane family, Apocynaceae. It is a perennial twining vine native to the southwestern and south-central United States and Mexico. It grows primarily in rocky woodlands, canyons, arid hillsides, and open wooded slopes, where its stems often trail across or climb through shrubs.[2][1]
The species is particularly recognizable by its distinctly wavy or crisped leaf margins, smooth inner corolla surfaces, constricted corona segments, and relatively long fruits.[3]
Description
[edit]Funastrum crispum is a perennial herbaceous vine with slender, twining stems. The stems climb through neighboring vegetation or trail across rocks and low shrubs.
The leaves are oppositely arranged and borne on short petioles. The blades are generally lance-shaped to broadly ovate. Their most distinctive feature is the noticeably undulating or crisped margin, which gives the foliage a ruffled appearance.[3]
The flowers are borne in clusters from the leaf axils. Like those of other milkweed relatives, they possess a five-parted corolla and a prominent central corona surrounding the reproductive column.
The corolla lobes are hairless on their upper or inner surfaces. The inflated corona segments are oblong and narrowed near the middle, giving each segment a constricted outline.[3]
The fruit is an elongated follicle. When mature, it splits open to release numerous flattened seeds, each bearing a tuft of silky hairs that assists wind dispersal.
Flowering may begin in early spring and continue through late summer. In some parts of its range, flowering and fruiting may continue into late autumn or early winter.[2]
Taxonomy
[edit]The species was originally described by British botanist George Bentham as Sarcostemma crispum. German botanist Rudolf Schlechter transferred it to the genus Funastrum in 1914.[4]
The current combination was published as:
- Funastrum crispum (Benth.) Schltr., Repert. Spec. Nov. Regni Veg. 13: 284. 1914.[4]
Its basionym was published as:
- Sarcostemma crispum Benth., Plantae Hartwegianae 291. 1849.[4]
Modern classifications place the species in Apocynaceae, although IPNI records the family used in Schlechter's publication as Asclepiadaceae. Asclepiadaceae is now generally treated as a subfamily within Apocynaceae.
The specific epithet crispum means “curled” or “wavy”, referring to the undulating margins of the leaves.
Identification
[edit]Funastrum crispum can be distinguished from other southeastern and south-central members of the genus by the combination of wavy leaf margins, hairless inner corolla surfaces, medially constricted corona segments, and elongated follicles.[3]
It differs from Funastrum clausum and Funastrum cynanchoides, both of which have flatter leaf margins and finely hairy inner corolla surfaces. Their corona segments are egg-shaped and lack the conspicuous medial constriction seen in F. crispum.[3]
Funastrum clausum generally occurs in wetter habitats, particularly in southern Florida and the lower Rio Grande Valley, whereas F. crispum is associated mainly with rocky and arid uplands. Funastrum cynanchoides also occupies dry habitats but differs in its flatter leaves, hairy corolla lobes, unconstricted corona segments, and shorter fruits.[3]
Distribution
[edit]Funastrum crispum is native to the southwestern and south-central United States and Mexico. In the United States, NatureServe records it from Arizona, California, Colorado, New Mexico, Oklahoma, and Texas.[1] [2]
Habitat and ecology
[edit]The species grows in rocky soils on hillsides, canyon slopes, and open wooded slopes. It is commonly found trailing over shrubs or climbing through low vegetation.[1]
Typical habitats include rocky woodlands, desert canyons, arid slopes, scrub, and open areas within dry woodland communities. The plant is associated with relatively sunny conditions but may use shrubs and small trees as structural support.[2]
Its twining growth allows it to reach above low vegetation without producing a self-supporting woody stem. The wind-dispersed seeds can potentially colonize open or recently disturbed rocky sites.
Conservation
[edit]NatureServe assigns Funastrum crispum, under the synonymous name Sarcostemma crispum, a global conservation rank of G4G5. This indicates uncertainty between apparently secure and secure. Its rounded global rank is G4, or apparently secure.[1]
The global assessment was last reviewed on 29 December 1993 and is identified by NatureServe as needing review. The species has not been assigned a national conservation rank in the United States.[1]
State conservation ranks include S1, or critically imperiled, in California and Oklahoma, and S2, or imperiled, in Colorado. It remains unranked in Arizona, New Mexico, and Texas. [1]
The species has no status under the United States Endangered Species Act.[1]
NatureServe considered it globally secure or apparently secure because it occupies relatively widespread and common habitats across Texas, Oklahoma, Colorado, New Mexico, Arizona, and Mexico. However, populations at the margins of the range may be uncommon or highly localized, as indicated by the state ranks in California, Colorado, and Oklahoma.[1]
References
[edit]- 1 2 3 4 5 6 7 8 9 "Sarcostemma crispum". NatureServe Explorer. NatureServe. Retrieved 22 July 2026.
- 1 2 3 4 Weakley, Alan S.; Southeastern Flora Team (2026). "Funastrum crispum". Flora of the Southeastern United States. Retrieved 22 July 2026.
- 1 2 3 4 5 6 Weakley, Alan S.; Southeastern Flora Team (2026). "Key to Funastrum". Flora of the Southeastern United States. Retrieved 22 July 2026.
- 1 2 3 "Funastrum crispum (Benth.) Schltr". International Plant Names Index. Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Herbarium. Retrieved 22 July 2026.