1Flowers actinomorphic. Perianth narrowed at the base and gradually, slightly widened towards the apex, always 3-lobed. Stamens 6-c. 36 (-46), in 1 or 2, rarely 3 or 4, whorls. Capsules usually siliquiform, elongated, ± 4-angular, 5-10 mm wide, 4-celled. Seeds oblong, ellipsoid, or broadly ovoid, in cross-section usually 3-angular. Stems usually erect, bearing small, bract-like leaves in the lower half, then one small leaf, followed by normal foliage leaves
1'Flowers zygomorphic. Perianth curved, consisting of 3 parts: the inflated basal utricle, the narrowed and neck-like tube, and the elongated, enlarged, or expanded, often 1-lipped, sometimes 3 (-6)-lobed limb. Stamens 6 (10 in A. decandra), always in 1 whorl. Capsules not siliquiform, often 6-angular or -ridged, (10-)15-40 mm wide, 6-celled. Seeds ovate, deltoid, or triangular, often flat. Stems usually scandent, also inerect species, bearing only foliage leaves