Sedum L.

10. Sedum L. View in CoL 1

Leaves usually alternate, seldom crowded into rosettes, and hardly ever (in European species) into the dense, globose rosettes characteristic of Sempervivum . Inflorescence usually cymose. Flowers hermaphrodite, usually 5-merous, but sometimes 4- or 6- to 9-merous. Petals free or slightly connate at the base, usually patent. Stamens usually twice as many as the petals, sometimes equal in number. Carpels equal in number to the petals. The habit of most species is characteristic, but it is difficult to frame a formal definition of the genus which delimits it clearly from Crassula , Sempervivum , and other genera, and the assignment of some species is still disputed. In addition to those described below several cultivated species are locally naturalized near gardens. Most European species favour dry, rocky or stony ground, and where no ecological information is provided this habitat may be presumed. Literature: R. L. Praeger, Jour. Roy. Hort. Soc. 46: 1-314 (1921). H. Fröderström, Acta Horti Gothob. 5-7 and 10 (1930-5).

1 Leaves flat, at least 8 mm wide; perennial

2 Petals bright yellow 3 Erect shrub with very stout stems 1. praealtum 3 Stems herbaceous except at the extreme base, fairly slender 4 Stems erect, usually all flowering 2. aizoon 4 Stemsprocumbentat base,bearingnon-floweringand flowering shoots 3. hybridum 2 Petals red, purple or whitish 5 Petals 10-12 mm, erect 7. spurium 5 Petals 3-5 mm, patent 6 Flowers whitish 4. telephium 6 Flowers pink or purple 7 Leaves dentate 4. telephium 7 Leaves entire

8 Leaves alternate 6. anacampseros

8 Leaves opposite 5. ewersii 1 Leaves less than 8 mm wide,often ± terete; perennialor annual 9 Petals yellow, cream-coloured or greenish-white 10 Follicles erect; leaves usually mucronate or apiculate;

flowers often 6- to 9-merous; stems 8-60 cm 11 Flowers few, in lax, unilateral cymes 12 Leaves of non-flowering shoots amplexicaul, with a membranous base; petals 6-8 mm 12. tenuifolium 12 Leaves not amplexicaul; petals 8-10 mm 13. pruinatum 11 Flowers numerous, in crowded cymes 13 Living leaves on non-flowering shoots confined to a terminal, tassel-like cluster; dead leaves persistent on lower part of shoot 11. forsteranum 13 Living leaves on non-flowering shoots not confined to a terminal cluster; dead leaves not persistent

14 Sepals 5-7 mm, glandular-puberulent; cymes flat-topped in bud and fruit 9. ochroleucum

14 Sepals 2-5-4- 5 mm, glabrous; cymes subglobose in bud,

concave in fruit

15 Inflorescence erect in bud; sepals ovate; leaves c. 4 mm

wide 8. sediforme

15 Inflorescence drooping in bud; sepals lanceolate; leaves

c. 2 mm wide 10. reflexum 10 Follicles ± patent; leaves obtuse; flowers 5-merous; stems

3-20 cm 16 Perennial (14-24). acre group 16 Annual or biennial 17 Petals scarcely exceeding the sepals; stamens usually 5

49. litoreum 17 Petals 2-3 times as long as sepals; stamens 10 48. annuum 9 Petals blue, pink or pure white 18 Stamens twice as many as the petals 19 Perennial, with leafy non-flowering shoots 20 Plant glabrous throughout

21 Flowers 4-merous 30. stefco

21 Flowers 5- to 9-merous

22 Leaves distinctly flattened, at least on upper side

23 Styles c. 0-75 mm 55. hispanicum

23 Styles c. 0-25 mm

24 Inflorescence racemose, elongate; follicles erect

34. magellense

24 Inflorescence a small, congested cyme; follicles stellate-patent 22. idaeum

22 Leaves ± terete

25 Leaves of non-flowering shoots opposite, 4-ranked

32. brevifolium

25 Leaves of non-flowering shoots alternate

26 Leaves subulate, acuminate 28. subulatum

26 Leaves linear to ovoid-globose, obtuse

27 Leaves spurred; stems 2-6 cm; cymes with 2-3

branches 29. anglicum

27 Leaves scarcely spurred; stems 5-18 cm; cymes with several branches

28 Petals white; inflorescence rather dense 25. album

28 Petals pink; inflorescence lax 26. serpentini 20 Plant pubescent or puberulent-papillose in part

29 Leaves mostly opposite or whorled

30 Leaves oblong-lanceolate, the upper ones whorled

33. monregalense

30 Leaves ovoid, never whorled 31. dasyphyllum 29 Leaves all alternate

31 Leavesglabrous 36. hierapetrae

31 Leavespubescentor puberulent-papillose

32 Leaves not much longer than wide

33 Leaves flat, glandular-pubescent, the lower ones stalked 35. alsinefolium

33 Leaves semiterete, puberulent-papillose, sessile

27. gypsicola

32 Leaves at least twice as long as wide

34 Flowers 6- to 9-merous; follicles stellate-patent

55. hispanicum

34 Flowers 5-merous; follicles erect

35 Peduncles arising from axils of rosette-leaves

37. tristriatum

35 Peduncles terminal

36 Buds drooping; carpels white; plant of dry rocks

38. hirsutum

36 Buds erect; carpels green or purple; plant of wet places 39. villosum

19 Annual or biennial; no non-flowering shoots present at flowering season

37 Petalssky-blue 57. caeruleum 37 Petalswhite, pink orpurple 38 Leaves dentate or crenate 47. stellatum

38 Leaves entire

39 Leavesmostlyoppositeor whorled 41. cepaea

39 Leavesalternate

40 Leaves pubescent

41 Flowers 6- to 9-merous; follicles stellate-patent

55. hispanicum

41 Flowers 5-merous; follicles erect

42 Biennial; inflorescence rather compact and narrow;

flowers stellate, erect 39. villosum

42 Annual; inflorescence lax and broad; flowers campanulate, drooping 42. lagascae

40 Leaves glabrous

43 Leaves 2-6 mm, terete, at least in apical half

44 Pedicels much longer than calyx 43. pedicellatum

44 Pedicels equalling or shorter than calyx

45 Leaves oblong or obovoid-clavate, flattened towards the base; branches erect 45. atratum

45 Leaves ovoid or ellipsoidal; branches diffuse,

ascending 44. arenarium

43 Leaves 7-20 mm, flat at least on upper surface

46 Leaves oblong-spathulate 40. creticum

46 Leaves linear

47 Flowers 6- or 9-merous; follicles stellate-patent

55. hispanicum

47 Flowers 5-merous; follicles ±erect

48 Sepals united for half their length; petals subacute 46. confertiflorum

Sepals free almost to base; petals

49 Follicles dark red 51. rubens

49 Follicles pale pink or whitish 56. pallidum

18 Stamens equal in number to petals 50 Flowers sessile or subsessile 51 Leaves ciliate-denticulate 50. aetnense 51 Leaves glabrous, entire 52 Leaves obovoid, imbricate 52. caespitosum

52 Leaves linear, patent 51. rubens

50 Flowers distinctly pedicellate 53 Biennial; leaves glandular-pubescent 39. villosum 53 Annual; leaves glabrous 54 Leaves ovoid or subglobose 53. andegavense

54 Leaves linear-oblong 54. nevadense