Flora of New Zealand Series

Annual or perennial herbs. Hairs glandular and/or eglandular or 0. Lvs opposite, exstipulate, linear-oblanceolate to linear to subulate, often glaucous; cauline lvs connate in pairs. Fls solitary or in lax to capitate cymes; bracts leaflike; epicalyx scales mucronate to obtuse, papery or membranous or scarious, rarely 0. Calyx narrowly cylindric or narrowed at apex, 5-toothed, with scarious veinless commissures between the teeth. Petals 5, pink or white, clawed or not, entire, 2-fid or toothed; coronal scales 0. Stamens 10. Styles 2. Fr. a cylindric to ovoid capsule, dehiscing by 4 teeth; carpophore usually present. Seeds flattened or folded around the hilum, scutate, warty or finely ridged, not winged.

c. 25 spp., mostly Mediterranean. Naturalised spp. 2.

The genus is close to Dianthus and Gypsophila; it differs chiefly from the former in the membranous veinless commissures of the calyx and from the latter in its seed structure and the presence of an epicalyx. The 2 spp. in N.Z. are superficially very similar but distinct in a few characters especially the seeds (Fig. 50).

Fig. 50. Petrorhagia, seeds. A P. prolifera; B P. velutina. © All rights reserved. [Image: 4X5A]