Romulea monadelpha (Sweet)

Manning, John C. & Goldblatt, Peter, 2001, the Arabian Peninsula and Socotra including new species, biological notes, and a new infrageneric classification, Adansonia (3) 23 (1), pp. 59-108 : 105-106

74. Romulea monadelpha (Sweet) Baker

Handbk. Irideae : 104 (1892); M.P. de Vos, J. S.

African Bot., Suppl. 9: 283 (1972); Fl. S. Africa 7(2),

fasc. 2: 68 (1983).

Trichonema monadelphum Sweet, Hort. Brit. ed. 2: 399 (1830). — Type: South Africa, Western Cape, without precise locality, illustration in Brit. Fl. Gard. 3: pl. 300 (1829) .

Plants 15-30 cm high, stem subterranean; corm rounded at base with curved acuminate teeth. Leaves 3-5, basal, filiform, 4-grooved, 1-2 mm diam.; outer bracts usually keeled above, with narrow, usually brown membranous margins, inner bracts 2-keeled with usually brown membranous margins. Flowers dark red with black blotches at the edge of a creamy cup, unscented, tepals obovate-cuneate, 25-40 mm long; filaments oblong, adnate or fused into a stout column, 3-4 mm long, usually glabrous, anthers 10-15 mm long. Fruiting peduncles curved. Flowering: Aug.-Sep.

Restricted to Northern Cape Province of South Africa, Romulea monadelpha occurs on dolerite clay in the western Karoo along the Bokkeveld and Roggeveld Escarpments from near Nieuwoudtville southwards as far as the top of the Gannaga Pass near Middelpos. The flowers are usually a deep red in color but the Gannaga Pass population has salmon pink flowers with unusually large silvery grey and black markings in the cup. Although R. monadelpha was originally distinguished from its ally R. sabulosa by the fused filament column, recent collecting shows that it is more usual for the filaments to be merely adnate. The filaments are, nevertheless, characteristically short, oblong in shape and black in color, and quite unlike the slender, tapering filaments of R. sabulosa , which are usually pale green. In addition, the peduncles in R. monodelpha are typically stout and semiterete with the upper side conspicuously flattened and are curved in fruit whereas those of R. sabulosa tend to be more slender and almost round in section and remain suberect in fruit. The two species differ also in habitat. Romulea monadelpha is found on heavy, dolerite clay in several localities along the Bokkeveld and Roggeveld Escarpments but R. sabulosa is a much narrower endemic restricted to light sandy clay soils near Nieuwoudtville.

— Ser. LOMUREA