Trifolium subterraneum L.
subclover
Annual; stems moderately to densely hairy, procumbent, not rooting at nodes. Lvs moderately to densely hairy especially on petioles and undersurface of leaflets; petioles c. 10-50-(200) mm long; leaflets broadly obovate, emarginate to obcordate or rarely obtuse at apex, obtuse at base, ± entire or very finely serrate toward apex, often with dark markings, c. 5-15 mm long; lateral veins thin and straight or somewhat recurved to leaflet margin; petiolules c. 1-1.5 mm long, ± equal; stipules ovate, acute. Infls axillary, umbellate, pedunculate, usually ± = subtending lf; fertile fls 2-5-(7), subsessile; sterile inner fls developing after anthesis; bracts 0. Calyx tube glabrous, with indistinct veins, somewhat inflated on all sides at fruiting; throat open, hairy; calyx teeth hairy, subequal, < corolla, linear, < tube, curled at fruiting; sinuses acute. Corolla white or occasionally pink, deciduous, 10-15 mm long. Calyx of sterile fls enlarged and recurved at fruiting enclosing the recurved young pods; infructescence appressed to or buried in soil by elongated peduncle. Pod glabrous, ± straight, < calyx, 2-3 mm long, 1-seeded; seeds c. 2 mm diam.
N.: occasional to locally common throughout; S.: locally common throughout except in Westland and Fiordland; St.: Halfmoon Bay, Mason Bay; K., Ch.
S. and W. Europe, Asia Minor, S. Russia, N.W. Africa 1906
Dry waste places, grassland, riverbeds.
FL Sep-Feb.
Subclover is widely cultivated as a pasture plant. It is distinguished from all other naturalised N.Z. clovers by the heads comprising few large fertile fls and central sterile fls the calyx of which expands at fruiting (Plate 13). N.Z. material can be referred to the type subsp. and var.
