Lepidium L.
Fls small, in racemes. Sepals obliquely ascending, not saccate; petals white, < or > sepals or absent; stamens often stunted or reduced to 4 or 2; style obsolescent to distinct; stigma capitate or 2-lobed. Silicles laterally much compressed, 2-seeded; valves keeled or winged above, reticulately veined; septum narrow, ovules pend. from apex of each cell; cots incumbent. Annual to perennial herbs or subshrubs. About 150 spp., some almost cosmopolitan. The N.Z. spp. are mostly endemic.
Key
Thellung (Die Gattung Lepidium (L.) R. Br., Zurich, 1906) groups the dioec. spp. under L. sisymbrioides Hook. f. :
1 Cauline lvs reducedsubsp. solandri (Kirk) Thell2
Cauline lvs conspicuous3
2 Silicles distinctly rhombic, style shortly exsertedvar. typicum Thell.
Silicles broadly ovate-rhombic, style distinctly exserted (East coast of Otago; Kurow)var. ovatum Thell.
3 Stem laxly branched above, branches spreading (including var. dubium (Kirk) Thell.)subsp. kawarau (Petrie) Thell.
Stem densely branched above4
4 Pinnules of basal lvs rotund, often entiresubsp. matau (Petrie) Thell.
Pinnules of basal lvs subpinnate-lobulate, lobules obtuse, rounded (Maniototo Plain)subsp. matau var. lobulatum Thell.
Further field and cultural work is necessary to determine the status of the forms of the dioec. spp. The occurrence of intermediate forms suggests that hybridism may occur. Cockayne and Allan (Ann. Bot., Lond. 48, 1934, 23) refer to a population suggesting the origin L. matau × kawarau.
