Digitalis L., 2002

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 : 239

17. Digitalis L. 1

Biennial or perennial herbs, rarely small shrubs. Leaves simple, alternate, sometimes mostly basal. Flowers in terminal, bracteate, often secund racemes. Calyx equally 5-lobed, shorter than the corolla-tube. Corolla with cylindrical to inflated-globose tube, often constricted at the base; limb more or less 2-lipped; lips erecto-patent, the upper shorter than the lower. Stamens 4. Capsule ovoid to conical, septicidal. Seeds numerous.

Literature: L. I. Ivanina, Acta Inst. Bot. Acad. Sci. U RSS (Ser. 1) 11: 198-302 (1955). K. Werner, Bot. Jahrb. 79: 218-254 (1960); Wiss. Zeitsehr. Univ. Halle (Math.-Nat. Kl.) 13: 453-486 (1964).

1 Middle lobe of lower lip of corolla projecting far beyond the others

2 Shrub; corolla-tube campanulate 1. obscura

2 Herb, sometimes woody at the base; corolla-tube inflatedglobose

3 Axis of inflorescence glandular-villous or -velutinous; corolla whitish with brown or violet veins

4 Bracts lanceolate; corolla 20-30 mm 11. lanata

4 Bracts linear; corolla 10-20 mm 12. leucophaea

3Axis of inflorescence glabrous and eglandular; corolla yellow to brown

5 Calyx-lobes obtuse, with a wide scarious margin 10. ferruginea

5 Calyx-lobes acute or acuminate, with scarious margin very narrow or absent 9. laevigata

1 Middle lobe of lower lip of corolla only slightly exceeding the others

6 Corolla-tube slender, cylindrical or cylindrical-urceolate

7Calyx-lobes ovate, obtuse 8. parviflora

7Calyx-lobes linear to lanceolate, acute

8 Plant pubescent or puberulent; corolla dull greenish-yellow, conspicuously veined 7. viridiflora

8 Plant ±glabrous (except in inflorescence); corolla pale yellow to whitish, not conspicuously veined 6. lutea

6 Corolla-tube stout, campanulate or campanulate-ventricose

9Corolla yellow; leaves ±smooth, usually glabrous above 5. grandiflora

9Corolla purple, pink or white; leaves ±rugose, usually hairy above

10 Whole plant covered with a yellowish, glutinous indumentum of glandular hairs 3. thapsi

10 Plant greenish to whitish, not or only slightly glutinous, with an indumentum of glandular and eglandular hairs

(rarely with eglandular hairs only or glabrous)

11 Corolla glabrous outside 2. purpurea

11 Corolla hairy outside

12 Lower leaves crenate to serrate, long-petiolate 2. purpurea

12 Lower leaves entire or shallowly dentate, shortly petiolate 4. dubia