Fls axillary, solitary, subtended by 2 bractlets, calyx deeply cut into 5 subequal lobes. Corolla-tube cylindric, upper lip entire or 2-fid, lower 3-fid. Stamens 2; staminodes 2, filiform, or lacking. Style filiform, stigma entire or 2-lamellate. Capsule ± ovoid, 4-valved, dehiscent from columnar axis. Seeds ∞, small, reticulate. Widespread genus of mostly perennial small glab. to glandular-pubescent herbs with opp., sessile, simple, entire or toothed lvs. Some 30 spp., the N.Z. spp. occurring also in Australia and Tasmania.