Arrowleaf

Gonolobus sagittifolius A. Gray, Proc. Amer. Acad. Arts 12: 77. 1876

Vines, suffrutescent, not corky. Stems 1–10, twining, 10–150 cm, retrorse-puberulent with curved, eglandular trichomes and inconspicuously glandular-hirtellous to glabrate. Leaves with 0–2 colleters on each side of petiole; petiole 0.2–1 cm, sparsely puberulent with curved, eglandular trichomes and inconspicuously glandular-hirsutulous; blade deltate to lanceolate or ovate, 0.5–2.5 × 0.2–1.3 cm, base shallowly to deeply cordate, with 2–4 laminar colleters, apex acute, surfaces sparsely puberulent with curved, eglandular trichomes and inconspicuously glandular-hirtellous (mostly on veins) to glabrate. Inflorescences solitary, umbelliform, extra-axillary, sessile or subsessile, 1–4-flowered. Pedicels 1–5 mm, puberulent with curved, eglandular trichomes and inconspicuously glandular-hirtellous. Flowers: calyx lobes ascending, linear to linear-lanceolate, 2–3 mm, apex acute, sparsely puberulent with curved, eglandular trichomes and inconspicuously glandular-hirtellous to glabrate; corolla green to yellow-green, not or very faintly reticulate, campanulate, tube 0.5–1 mm, lobes ascending, linear, 5–10 mm, apex often twisted, gla­brous; corona cup-shaped, apex undulate, with 5 paler appendages opposite anthers, exceeded by style apex, green, cream, or yellowish, 0.5–0.7 mm, glabrous; apical anther appendages white, deltoid; style apex yellow, pentagonal-lobed, flat to broadly convex. Follicles gray to maroon or purplish striate, lance-ovoid, 6–7 × 1–2 cm, apex acuminate, smooth to very sparsely tuberculate, mostly on lower half, minutely puberulent to glabrate. Seeds tan, ovate, 5–7 × 4–5 mm, margins winged, chalazal end minutely erose, faces rugulose; coma 2–3 cm.

Flowering Mar–May(–Oct); fruiting Apr–Dec. Hills, slopes, ridges, limestone, sandstone, rocky and sandy soils, thornscrub, desertscrub; 20–700 m; Tex.; Mexico (Nuevo León, Tamaulipas).

Matelea sagittifolia is a vigorously twining, drought-deciduous vine. Its range in Texas extends from the Rio Grande Valley, (Terrell County to Starr County) northward and eastward to McMullen and San Patricio counties, where the species is uncommon. Distinctions between M. sagittifolia and the highly similar 10. M. parvifolia and 12. M. radiata are discussed under those species.