Flora of New Zealand Series

Annual herbs. Lvs 2-3-pinnatisect, alternate. Capitula solitary, terminal, sessile; involucral bracts in 1-2 rows, with narrow membranous margins. Receptacle flat; scales 0. Outer florets ♀, without a corolla; inner florets ⚥ or functionally ♂, tubular. Achenes all similar, strongly compressed, glabrous or hairy but not glandular; outer surface often with a central rib; lateral angles winged or not; style persistent, spinous; pappus 0.

3-5 spp., S. America. Naturalised spp. 2.

Soliva has been revised by Cabrera, A. L., Notas Mus. La Plata (Bot.) 14 : 123-139 (1949). The spp. naturalised in N.Z. are discussed by Healy, A. J., Trans. Roy. Soc. N.Z. 81 : 23-26 (1953).

As a result of field and cultivation studies of plants in N.Z. the treatment provided here differs markedly from that of Healy, Cabrera, and overseas Floras [Webb, C. J., New Zealand J. Bot. 24 : 665-669 (1986); see also, Lovell, P. H., Maxwell, C. D. and Jacob, N., New Zealand J. Bot. 24 : 657-664 (1986)]. Forms treated as the 4 distinct spp. of subgen. Soliva by Cabrera (op. cit.) are all included here under S. sessilis. Subgen. Gymnostyles also probably contains fewer good spp. than described by Cabrera; this subgenus is given generic rank as Gymnostyles A. L. Juss in some treatments [e.g., Tutin, T. G., in Fl. Europ. 4 : 178 (1976)], but the achene characters used are insufficient to justify generic separation when variability in achene morphology within the single sp. of subgen. Soliva is considered.

Both naturalised spp. have increased in distribution since 1953 and further spread, chiefly by human dispersal, can be expected.