Vicia unijuga A. Br. - One-paired Vetch.

Taxonomic position.

Family Fabaceae Lindl., genus Vicia L.


Orobus lathyroides L.

Morphology and biology.

Perennial herbaceous plant with thick rhizome. Numerous stems 50-60 cm tall, erect, ribbed, pubescent or subglabrous. Leaves shortly petiolate, consist of one pair of leaflets. Leaflets 60-80(90) mm long, 25-35(50) mm wide, large, oblong-elliptic or elliptic with attenuate apex, somewhat rigid, finely cartilaginously dentate at margins, glabrous on both surfaces. Leaf rachis ends in a linear-subulate prickle 2-3 mm long. Stipules 10-12 mm long, large, semilunar, with one acute and one largely dentate lobe. Peduncles much exceed the leaves axils from which they arise. Raceme composed of 10-15(20) flowers. Flowers 13-14 mm long, violet or blue-mauve. Calyx teeth short, triangular-subulate. Standard and wings slightly longer than keel. Standard oblong, reflexed from keel. Style dorsally compressed, evenly pubescent. Pods 22-25 mm long, oblong-lanceolate, fulvous-brown with attenuate beak. Seeds black-brown. Hilum as long as 1/4 of the seed circuit.
Entomophilous. Autochore. Flowers in July - August, mature fruits in August - September. 2n=12, 24, 36.


Widespread East Asian species. Southern Siberia (from Altai-Sayan mountain systems in the west, to Stanovoy Range in the east), Russian Far East (Amur Region, Khabarovsk and Primorie Territories, Sakhalin Island, Kuril Islands - Shikotan, Kunashir, Iturup, Urup), Mongolia (north), China (north), Korean Peninsula (north), Japan.


Mesophyte. Shade-resistant. Occurs in mixed, birch, pine and larch forests and their fringes.

Use and economic value.

Ornamental, forage.


Nikiforova OD. 1988. Wild vetches of Siberia. Novosibirsk: Nauka. 136 p. (In Russian).
Kharkevich SS., ed. 1989. Vascular plants of the Soviet Far East. V.4. Leningrad: Nauka. 380 p. (In Russian).
Polozhij AV., Malyshev LI., ed. 1994. Flora of Siberia. V.9. Fabaceae (Leguminosae). Novosibirsk: Nauka. P.183-184. (In Russian).

© I.G.Chukhina

© Photo by M.G.Kutsev

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