Helleborus L.

1. Helleborus L. View in CoL 1

Perennial herbs with rhizomes or erect, rather woody stems and digitate or pedate leaves. Inflorescence cymose. Flowers large; perianth-segments 5; honey-leaves 8-12, obliquely infundibuliform, smaller than the perianth-segments; involucre absent. Fruit of 3-8, several-seeded follicles. The treatment of spp. 3-10 is based on H. Merxmiiller &

D. Podlech, Feddes Repert. 64: 1-8 (1961). 1 Rhizome absent; stems overwintering, ±w oody; leaves all cauline

2 Leaf-segments 7-11; flowers campanulate 1. foetidus

2 Leaf-segments 3; flowers with widely spreading perianthsegments 2. lividus

1 Rhizome present; stems of short duration, herbaceous; basal leaves present

3 Bracts entire 11. niger

3 Bracts divided and leaf-like

4 Follicles free to base, shortly stipitate

5 Flowers cream at first, becoming greenish-yellow-brown; leaves overwintering 4. orientalis 5 Flowers clear green; leaves not overwintering 3. cyclophyllus 4 Follicles connate at base for about | their length 6 Flowers reddish or purplish, at least outside 7 Leaves entirely glabrous, even on the slender inconspicuous veins beneath 9. dumetorum 7 Leaves pubescent, at least on the stout prominent veins beneath 8 Leaves digitate; flowers 4-6 cm in diameter

10. purpurascens 8 Leaves pedate; flowers 3-4-5 cm in diameter 7. multifidus 6 Flowers greenish with no reddish or purplish tinge 9 Flowers at most 3-5-4 cm in diameter, nodding; perianthsegments not or scarcely imbricate 10 Leaves pubescent, at least on the prominent veins beneath; cauline leaves small 7. multifidus 10 Leaves glabrous or nearly so, even on the slender veins beneath; cauline leaves large

11 Leaves very finely dentate; flowers unscented, overtopped by the leaves 9. dumetorum

11 Leaves coarsely incise-dentate; flowers scented, overtopping the leaves 5. viridis 9 Flowers at least 4 cm in diameter, not or slightly nodding at anthesis; perianth-segments imbricate 12 Flowers 4-5 cm in diameter, yellow-green; veins slender,

but prominent beneath 5. viridis 12 Flowers 5-7 cm in diameter, yellowish; veins stout, very prominent beneath

13 Leaf-segments 7-11, undivided or with the marginal ones somewhat divided 6. odorus

13 Leaf-segments usually 5-7, more deeply divided

14 Leaves usually entirely glabrous; basal c. 10 cm wide;

cauline little smaller 8. bocconei

14 Leaves pubescent, at least on the veins beneath; basal

20-30 cm wide; cauline much smaller

15 Leaf-segments linear-lanceolate, most or all 2- to

10-fid, coarsely dentate 8. bocconei

15 Leaf-segments wider, some undivided, others 2- to

5-fid, finely dentate 6. odorus