Petalidium

Shrublets or procumbent, perennial herbs. Leaves varying from ovate to linear. Inflorescence axillary, scorpioid or dichasial cymes, with few to many flowers; lower bracts present or 0, ultimate 2 bracts large, enclosing calyx. Calyx regular, glandular; lobes 4 or 5, when 4 then anticous one usually bifid or 2-toothed and lateral ones smaller; tube shorter than lobes. Corolla +/- 2-lipped; upper lip 2-lobed; lower lip 3-lobed, with palate transversely ribbed and furnished with retrorse hairs; lobes obovate, obtuse or emarginate; aestivation contorted; rugula indistinct; tube longer than lobes, straight or curved, usually cylindric below and campanulate above. Androecium: fertile stamens 4, didynamous, arising at +/- middle of corolla tube, included; filaments arising in pairs, broadly linear; anthers 2-thecous; thecae parallel, muticous or mucronate at base; staminodes 0. Pollen prolate, 3-porate, with pseudocolpi; pore lipped; surface reticulate. Disc annular. Gynoecium: ovary with 2 ovules in each locule; style terete, pubescent; style branches 2, equal, cylindriform. Capsule estipitate, compressed, narrowed at base and apex, with elastic placental bases. Seeds orbicular, with hygroscopic hairs over whole surface. x = 8 (polyploidy).