Corchorus

Herbs, annual or perennial, [subshrubs], or shrubs, taprooted. Stems erect to ascending or decumbent, usually unbranched or relatively few-branched, hairy, hairs simple or stellate. Leaves petiolate; stipules caducous to subpersistent, filiform; blade unlobed, oblong to ovate obovate, apically awned or not, glabrous or hairy; petals [4 or]5, yellow, obovate to oblanceolate, glands absent; stamens [4–]10–70[–100], on androgynophore; ovary 2–4[–10]-locular; ovules 2–50 per locule; styles 1, simple, short-cylindric; stigmas peltate or discoid, usually irregularly crenulate or lobulate. Capsules usually cylindric to short-ellipsoid, rarely subglobose, 2–4[–10]-valved, glabrous or hairy, dehiscence loculicidal. Seeds 4–10[–30] per locule, angular, smooth or pitted. x = 7.

Distribution

United States, Mexico, West Indies, Central America, South America, se Asia, Africa, Pacific Islands, Australia.

Discussion

Corchorus capsularis Linnaeus and C. olitorius Linnaeus have been domesticated for production of bast fibers and are the commercially important cultivated species. Corchorus aestuans Linnaeus also is used and cultivated for fiber production, although the fibers are weaker than those of the others. Fibers of other species (for example, C. tridens Linnaeus) also are used locally. Corchorus leaves (C. capsularis in China and Japan; C. olitorius in southern Asia, the Middle East, and northern Africa) are commonly eaten as leafy vegetables and in stews. Within C. olitorius, the fiber types and the vegetable types comprise two separate cultivar groups, the former with a little-branched habit.

Generic boundaries among the species of Corchorus probably will be modified. The monospecific Oceanopapaver Guillaumin is part of a clade with the endemic Malagasy genus Pseudocorchorus Capuron and species of Corchorus with stellate vestiture (C. Tirel et al. 1996; B. A. Whitlock et al. 2003).

Species 90–100 (5 in the flora).

Selected References

None.

Lower Taxa

Corchorus aestuans, Corchorus hirsutus, Corchorus hirtus, Corchorus siliquosus, Corchorus tridens

Key

1	Stems, leaves, and fruits densely tawny-pubescent, hairs stellate; capsules subglobose to short-ellipsoid.	Corchorus hirsutus
1	Stems, leaves, and fruits glabrous or sparsely hairy, hairs simple; capsules cylindric	> 2
2	Capsules 3(–4)-valved, each valve terminated by bifurcate awn	> 3
2	Capsules 2-valved, awns none or not bifurcate	> 4
3	Capsules 4–5 mm diam., wing-angled, awns 1.5–3 mm; pedicels 2–3 mm; sepals awned.	Corchorus aestuans
3	Capsules 1.5–2 mm diam., not wing-angled, awns 1.5–2 mm; pedicels 0–1 mm; sepals not awned.	Corchorus tridens
4	Stems puberulent in lines, hairs retrorse, blunt-tipped; capsules terete, sparsely to moderately strigose to strigulose, distally abruptly constricted to beaklike apex, awnless; sepals hirsute; stamens 15–25.	Corchorus hirtus
4	Stems short-pilose in 1(–2) lines, hairs erect, sharp-tipped; capsules flattened, minutely hirtellous to hispidulous, distally subtruncate, each valve 2-awned; sepals glabrous; stamens 50–70.	Corchorus siliquosus