Flora of New Zealand Series

sulphur clover

Shortly rhizomatous perennial; stems sparsely hairy below, moderately to densely clothed in appressed hairs in upper parts, erect or ascending. Lvs moderately to densely hairy on both surfaces; petioles sparsely hairy, up to 100 mm long; leaflets elliptic to narrowly obovate, obtuse to emarginate, usually shortly mucronate, cuneate at base, ± entire or very finely serrate near apex, usually unmarked, 15-30-(50) mm long; lateral veins thin and ± straight to leaflet margin; petioles 1-2 mm long, ± equal; stipules broadly ovate, acuminate. Infls terminal, spicate, globose to ovoid, ± sessile, > subtending lvs; fls numerous, sessile; bracts 0, but stipules of subtending lvs partly enfolding young infl. Calyx moderately hairy, 10-veined, not inflated at fruiting; throat open, with a ring of hairs, thickened at fruiting; calyx teeth unequal, much < corolla, linear with slightly broader base, spreading at fruiting; upper teeth < tube; lowest tooth 2-3× as long as other 4, > tube; sinuses mostly acute. Corolla yellowish white, ultimately deciduous, c. 15 mm long. Pod glabrous, straight, < calyx, thickened at apex, 2-3 mm long, 1-seeded; seeds c. 2 mm long, with a blunt projection on one side.

S.: known from one recent collection only, oversown foothill pasture, Hokonui Hills, Southland, 20.2.1983.

W., C. and S. Europe, Asia Minor, N. Africa 1880

There are a few early records of sulphur clover naturalised in N.Z. but Healy, A. J., Identification of Weeds and Clovers ed. 3 (1982), noted that there is only one collection in the last 35 years. The new record from Southland indicates that it may still persist in some areas or may occasionally be reintroduced as a seed impurity. The sp. is superficially similar to white-flowered forms of red clover but is distinguished by the narrower, hairier leaflets and the much longer lowermost calyx tooth.