Herbs, annual, unarmed. Stems erect or sprawling, ribbed, branched, glabrous. Leaves alternate, even-pinnate; stipules present, foliose, usually larger than leaflets, without nectariferous patch; rachis winged, usually terminating in branched tendril; petiolate; leaflets [2 or]4 or 6[or 8], opposite, folded in bud, stipels absent, blades usually becoming smaller from base of rachis, margins entire or dentate, surfaces glabrous. Inflorescences 1–3[or 4]-flowered, axillary, racemes, erect or lax; bracts present, caducous, bracteoles absent. Flowers papilionaceous; calyx campanulate, base symmetric, lobes 5, equal, lanceolate, exceeding tube; corolla white or bicolored (banner lilac, wings reddish purple), 15–30 mm; stamens 10, diadelphous; anthers basifixed; ovary glabrous or pubescent; style abaxially compressed, folded longitudinally, laterally pubescent. Fruits legumes, sessile, terete, oblong-linear, dehiscent, non-septate, margins usually obscure, splitting, glabrous; valves twisted after dehiscence. Seeds 3–10, globose or angular, smooth or papillose, sometimes wrinkled. x = 7.

Distribution

Introduced; s Europe, sw Asia, n Africa, introduced also in n Europe, n, c Asia.

Discussion

Species 3 (1 in the flora).

Pisum consists of three closely related species (O. E. Kosterin and V. S. Bogdanova 2008; P. Smýkal et al. 2011). Pisum sativum includes both culinary and forage varieties, which are widely cultivated in North America.

Recent phylogenetic studies have placed Pisum consistently within the Vicieae (M. F. Wojciechowski et al. 2004; H. Schaefer et al. 2012).

Selected References

None.

Lower Taxa

Pisum sativum