Luffa

Plants annual, monoecious, climbing or trailing; stems villous or hirsute to scabrous; roots fibrous; tendrils [2–]3–6-branched. Leaves: blade suborbiculate to ovate-cordate [triangular], palmately (3–)5–7-lobed, [rarely subentire], lobes broadly ovate to triangular, suborbiculate, oblong-ovate, oblong-triangular, or depressed-ovate, margins entire or sinuate, sinuate-toothed, sublobulate-dentate, or coarsely dentate, surfaces eglandular or gland-dotted. Inflorescences: staminate flowers (5–)15–20 in axillary racemes, opening one at time in sequence acropetally; pistillate flowers solitary, in same or different axils as staminate; bracts caducous, linear. Flowers: hypanthium campanulate; sepals 5, erect, straight, triangular-lanceolate; petals 5, distinct, yellow, obcordate to obovate, oblong-obovate, or obovate-cuneate, 20–45 mm, glabrous, corolla shallowly campanulate [rotate, ± flat]. Staminate flowers: stamens (3–)5, one 1-locular, others 2-locular or all monothecous; filaments inserted on or near hypanthium rim, distinct; thecae connate, sigmoid, contorted, connective slightly broadened; pistillodes absent. Pistillate flowers: ovary 3(–6)-locular, subglobose to cylindric; ovules 30–100 per locule; style 1, columnar; stigmas 3, 2-lobed; staminodes 3(–5). Fruits pepos, usually greenish, sometimes white-striped, drying brownish, cylindric to narrowly clavate [subglobose], (6–)15–50 cm, smooth [ribbed, aculeate-scabrous, or densely echinate], glabrous, with rigid internal network of fibrovascular bundles, dehiscent by apical operculum. Seeds 100–300, broadly ellipsoid to oblong-ellipsoid or ellipsoid-ovoid, compressed, not arillate, sometimes with broad beak, margins winged or not, surface smooth or roughened. x = 13.

Distribution

Central America, South America, Asia.

Discussion

Species 7 (2 in the flora).

Young and tender fruits of both species of Luffa in the flora area are used as vegetables. The mature fruit is inedible due to the hardened network of fibrovascular bundles that forms the loofah “sponge.” The sponges are commonly used for scrubbing and cleaning.

Four Luffa species are native in the Old World (including the two treated here) and three in the New World. Both of the widely cultivated species, L. acutangula and L. aegyptiaca, apparently originated in the India-Pakistan region and are closely related to each other (B. Dutt and R. P. Roy 1990; C. B. Heiser and E. E. Schilling 1990). The Asian species are more distinctly differentiated among themselves than are the American ones.

Selected References

Ali, M. A., S. Karuppusamy, and F. M. A. Al-Hemaid. 2010. Molecular phylogenetic study of Luffa tuberosa Roxb. (Cucurbitaceae) based on internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA and its systematic implication. Int. J. Bioinf. Res. 2: 42–60.

Heiser, C. B. and E. E. Schilling. 1990. The genus Luffa: A problem in phytogeography. In: D. M. Bates et al., eds. 1990. Biology and Utilization of the Cucurbitaceae. Ithaca, N.Y. Pp. 120–133.

Lower Taxa

Luffa acutangula, Luffa aegyptiaca

Key

1	Pepos narrowly clavate, 10-angled; petals pale yellow; seeds beaked, beak margins obscurely winged.	Luffa acutangula
1	Pepos cylindric, not angled; petals bright yellow; seeds not beaked, margins with wings ca. l mm wide.	Luffa aegyptiaca