Hyoscyamus L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 195

5. Hyoscyamus L. 1

Annual, biennial or perennial herbs, often viscid. Leaves alternate, simple. Flowers axillary, in bracteate spikes or racemes. Calyx campanulate-tubular, 5-dentate, 10- or more veined, accrescent. Corolla usually broadly infundibuliform, with 5 obtuse lobes. Stamens usually slightly exserted, inserted at base of corolla. Stigma capitate. Fruit a capsule, included in the calyx, circumscissile; seeds reniform to orbicular.

1 Cauline leaves sessile

2 Cauline leaves amplexicaul;corollapaleyellow, usuallywith purpleveins; fruiting calyx ventricose 1. niger

2 Caulineleaves notamplexicaul; corolla purple with darker reticulate veins; fruiting calyx tubular 2. reticulatus

1 Leaves all petiolate

3 Corolla 1-1- 5(—2) cm, usually slightly exceeding calyx 5. pusillus

3 Corolla at least 2-5 cm, much exceeding calyx

4 Flowers sessile, except the lowest, in a dense spike; corolla usually yellowish-white 3. albus

4 Flowers all shortly pedicellate, in a lax, few-flowered raceme; corolla golden yellow 4. aureus