Alkanna Tausch (1824: 234) .

Type:— Alkanna tinctoria (Linnaeus) Tausch (1824: 234) .

Perennial herbs, flowers often sweet-scented. Leaves variously puberulous, pilose and setose, indumentum ranging from slender glandular and eglandular hairs to robust setae. Inflorescence terminal; cymes 1-several, bracteate. Calyx divided nearly to base into lanceolate-linear lobes, stellately opening after abscission of fruit. Corolla slightly irregular, blue, yellow or white limb and often darker tube, infundibular; throat with a ring of hairs and sometimes with small invaginations. Annulus small, glabrous or ciliate. Stamens included; filaments very short, inserted in a whorl or spiral near the middle of tube; anthers oblong, obtuse. Style not exserted; stigma small, entire. Nutlets l–2(–4), subreniform to obliquely ovoid, rugose or finely tuberculate, scrobiculate or reticulate, often in combination, rarely smooth; beak straight and horizontal to curved.