Family |
Fabaceae
Lotus tetragonolobus
L.
Lotus tetragonolobus L.
(Sp. Pl.: 773; 1753 – Nouvelle Flore du Liban et de la Syrie, vol. 2, Pl. CLXXV nº 3; 1969)
• Life-form & habit: Annual herb, 10–40 cm tall, decumbent to ascending, with slender, branching stems often forming low mats. Stems and leaves sparsely pubescent, green to reddish at nodes.
• Leaves: Alternate, trifoliolate with two large stipules resembling additional leaflets. Leaflets obovate to oblong, 10–20 × 4–8 mm, entire or slightly toothed near the tip, glabrous or sparsely hairy on both sides; stipules ovate, foliaceous, nearly as large as the lower leaflets.
• Inflorescence & flowers: Peduncles solitary, axillary, longer than the subtending leaf, bearing 1–2 flowers. Flowers papilionaceous, 12–18 mm long, bright red to crimson (rarely yellowish-red); standard broad, spreading; wings and keel shorter. Calyx campanulate, teeth triangular, about half the length of the tube.
• Fruit: Pod 20–40 mm long, distinctly four-winged along its angles, a diagnostic feature of the species; valves glabrous or sparsely pubescent, seeds numerous, olive to dark brown.
• Phenology: Flowers and fruits from March to June.
• Habitat & elevation: Dry, open grassy slopes, coastal dunes, and light calcareous or sandy soils; from sea level up to c. 1 200 m. Prefers sunny, well-drained sites, often near the coast or in open Mediterranean scrub.
• Lebanese distribution: Recorded by Mouterde from Beirut, Aley, Saida, and the coastal hills of Mount Lebanon; rare inland, occasional in disturbed fields and rocky slopes at low to mid elevations.
• Native to: Algeria, Baleares, Cape Verde, Corse, Cyprus, East Aegean Is., Egypt, Greece, Italy, Krym, Lebanon-Syria, Libya, Morocco, Palestine, Sardegna, Sicilia, Sinai, Spain, Tunisia, Türkiye, Ukraine (POWO).
• Introduced into: Baltic States, Canary Is., Czechia-Slovakia, France, Germany, New South Wales, Portugal, Victoria (POWO).
• ⚠️ Taxonomic note: Lotus tetragonolobus — commonly known as “winged lotus” or “astragalus à quatre ailes” — is easily distinguished from other Lotus species by its conspicuously four-angled, winged pods and bright red flowers. Mouterde (1969) described the Lebanese populations as coastal and low-montane, favouring light, open soils and frequently associated with Medicago minima, Trifolium stellatum, and Vicia sativa. It is both ornamental and occasionally used as forage in Mediterranean grasslands.