Sedum

Herbs, annual, biennial, or perennial, rarely subshrubs, not viviparous, 0.2–10 dm, glabrous or hairy. Stems erect, ascending, procumbent, or creeping, usually much-branched, sometimes succulent, usually hardly secondarily thickened, base sometimes slightly woody. Leaves deciduous or persistent, rarely rosulate, sometimes forming dense rosettes, usually alternate, sometimes opposite or in whorls of 3–5[–6], ± alike, petiolate or sessile, not connate basally; blade linear to orbiculate or spatulate, terete, semiterete, or subterete, rarely laminar, 0.1–8 cm, usually ± succulent, base spurred or not, margins entire, (with 1 abaxial apical hydathode); veins not conspicuous. Inflorescences terminal or axillary cymes (sometimes compound, cincinnate, less often simple). Pedicels present or absent. Flowers erect, (3–)5–8[–12]-merous; sepals distinct and spurred or slightly connate basally, (green), equal or strongly unequal; petals spreading or erect at anthesis, usually distinct or slightly connate basally, [connate for 1/3–2/3 their lengths], yellow, white, pink, purple, or reddish, sometimes red-lineolate (often with reddish keel and adaxial subapical appendage), margins entire; calyx and corolla not circumscissile; nectaries oblong, square, transversely oblong, reniform, or spatulate; stamens 2 times as many as sepals, rarely as many as sepals; filaments of epipetalous stamens usually adnate basally, filaments of antipetalous stamens usually distinct, rarely connate basally; pistils erect, slightly connate basally to almost distinct, (usually sessile with broad base); styles equaling or shorter than ovary. Fruits erect or spreading. Seeds ovoid to ellipsoid, (usually ca. 1 mm), reticulate or reticulate-papillose. 2n = 4–ca. 640.

Distribution

North America, Mexico, Central America, Europe, Asia, n, e Africa, Atlantic Islands (Iceland), Indian Ocean Islands (Madagascar).

Discussion

Amerosedum Á. Löve & D. Löve; Breitungia Á. Löve & D. Löve; Chetyson Rafinesque; Clausenella Á. Löve & D. Löve; Cockerellia (R. T. Clausen & C. H. Uhl) Á. Löve & D. Löve; Hjaltalinia Á. Löve & D. Löve

Species 420–470 (41 in the flora).

Many genera of Crassulaceae currently recognized are derived from Sedum, the largest genus in the family. Molecular studies by H. ’t Hart (1995), R. C. H. J. van Ham and ’t Hart (1998), ’t Hart et al. (1999), S. Mayuzumi and H. Ohba (2004), and M. E. Mort et al. (2001) have formed the basis for recognizing segregate genera when the nomenclatural, biogeographic, and morphological data also have been available. Such data are still lacking for many other groups, and these are retained in Sedum pending further study. R. T. Clausen (1975) provided the most comprehensive treatment to date of native and naturalized Sedum in North America.

Selected References

Calie, P. J. 1981. Systematic studies in Sedum section Ternata (Crassulaceae). Brittonia 33: 498–507.

Clausen, R. T. 1975. Sedum of North America North of the Mexican Plateau. Ithaca, N.Y.

Denton, M. F. 1982. Revision of Sedum section Gormania (Crassulaceae). Brittonia 34: 48–77.

Fröderström, H. A. 1930–1935. The genus Sedum L.: A systematic essay. Acta Horti Gothob. 5(app.), 6(app.), 7(app.), 10(app.).

Lower Taxa

Sedum acre, Sedum albomarginatum, Sedum album, Sedum annuum, Sedum borschii, Sedum cockerellii, Sedum debile, Sedum divergens, Sedum glaucophyllum, Sedum havardii, Sedum hispanicum, Sedum lanceolatum, Sedum laxum, Sedum leibergii, Sedum lineare, Sedum mexicanum, Sedum moranii, Sedum nanifolium, Sedum nevii, Sedum niveum, Sedum nuttallii, Sedum oblanceolatum, Sedum obtusatum, Sedum ochroleucum, Sedum oreganum, Sedum oregonense, Sedum praealtum, Sedum pulchellum, Sedum pusillum, Sedum radiatum, Sedum robertsianum, Sedum rupestre, Sedum rupicola, Sedum sarmentosum, Sedum sexangulare, Sedum spathulifolium, Sedum stelliforme, Sedum stenopetalum, Sedum ternatum, Sedum villosum, Sedum wrightii

Key

1	Annual or biennial herbs	> 2
1	Perennial herbs or subshrubs	> 14
2	Biennial herbs	> 3
2	Annual herbs	> 7
3	Flowering shoots forming axillary offsets	> 4
3	Flowering shoots not forming axillary offsets	> 5
4	Filaments white; carpels stellately spreading in fruit	Sedum radiatum
4	Filaments yellow; carpels divergent in fruit.	Sedum stenopetalum
5	Petals canary yellow; sepals slightly connate basally, glabrous.	Sedum leibergii
5	Petals pink-red or purple to white; sepals distinct, glabrous or glandular-hairy	> 6
6	Stems and leaves glabrous; sepals glabrous; petals white to purple, 4-10 mm.	Sedum pulchellum
6	Stems and leaves hirtellous and glandular-hairy; sepals glandular-hairy; petals pink-red, 3-4.5 mm	Sedum villosum
7	Stems glandular-hairy (at least distally) or hirtellous	> 8
7	Stems glabrous	> 9
8	Stems hirtellous; leaf blades hirtellous and densely glandular-hairy; sepals 2-4 mm.	Sedum villosum
8	Stems glandular-hairy; leaf blades usually glabrous, rarely glandular-hairy; sepals ca. 2 mm.	Sedum hispanicum
9	Petals 4-11 mm	> 10
9	Petals 1.4-5 mm	> 12
10	Flowering shoots without axillary offsets; c, e United States.	Sedum pulchellum
10	Flowering shoots with axillary offsets; w United States	> 11
11	Carpels stellately spreading in fruit.	Sedum radiatum
11	Carpels divergent in fruit.	Sedum stenopetalum
12	Petals white, ovate-elliptic.	Sedum pusillum
12	Petals yellow, elliptic-oblong or narrowly lanceolate	> 13
13	Leaf blade bases short-spurred; petals elliptic-oblong; c United States.	Sedum nuttallii
13	Leaf blade bases not spurred; petals narrowly lanceolate; Greenland.	Sedum annuum
14	Petals white, creamy white, yellowish white, pale yellow, yellowish, white tinged with purple or streaked with pink, pinkish white, greenish white, purple, pink-red, or pink	> 15
14	Petals yellow, yellowish green, golden yellow, pale orange, or pale orange suffused with pink	> 32
15	Flowers mostly 4-merous, sometimes 5-6(-7)-merous	> 16
15	Flowers mostly 5(-8)-merous	> 19
16	Leaf blades of flowering stems linear, base sagittately spurred.	Sedum pulchellum
16	Leaf blades of flowering shoots obovate to obovate-spatulate or elliptic, narrowly elliptic, oblong or linear, base short-spurred	> 17
17	Leaves whorled, usually 3, sometimes 2 or 4 per whorl, sometimes decussate.	Sedum ternatum
17	Leaves alternate	> 18
18	Leaf blades not glaucous; petals acute apically; primary rosettes usually 1 cm diam.	Sedum nevii
18	Leaf blades usually glaucous; petals acuminate apically; primary rosettes usually 1-2.7 cm diam.	Sedum glaucophyllum
19	Flowers pungent, musky scented (unique in the flora area); petals sharply curved outward 2/3 from erect base, distal 1/3 divergent	Sedum wrightii
19	Flowers without pungent scent; petals erect, widely spreading from base, or spreading from middle, not sharply curved outward	> 20
20	Inflorescences panicles or paniculate cymes	> 21
20	Inflorescences 1-3(-5)-parted or branched cymes, corymbs, or corymbiform cymes	> 25
21	Stems creeping and short-ascending, basally densely glandular- pubescent; petals 2-4.5 mm.	Sedum album
21	Stems rootstocks or stout rhizomes, bearing rosettes, glabrous; petals 4-11.5 mm	> 22
22	Leaf blades narrowly obovate, strongly pruinose, not glaucous; sepals 4-7 mm.	Sedum oblanceolatum
22	Leaf blades obovate, spatulate, or oblanceolate, not strongly pruinose, sometimes glaucous; sepals 1.8-6 mm	> 23
23	Petals 4-10 mm; sepals loosely appressed to corolla, 1.8-5.3 mm; flowering shoots 2-10(-12) cm.	Sedum obtusatum
23	Petals ca. (4-)7-11.5 mm; sepals closely appressed to corolla, (2-)2.6-5.1 mm; flowering shoots (6-)10-28(-40) cm	> 24
24	Petals pink, pinkish white, or white, apices obtuse; sepals 2.6-5.1 mm	Sedum laxum
24	Petals creamy white, yellowish white, or pale yellow, apices abruptly pointed; sepals 3.2-3.5 mm.	Sedum oregonense
25	Leaf blades of flowering shoots linear or linear-lanceolate to linear-oblanceolate	> 26
25	Leaf blades of flowering shoots lanceolate, obovate to oblanceolate, oblanceolate-elliptic, elliptic-ovate, oblong-spatulate, oblanceolate-oblong, spatulate, or elliptic to elliptic-oblong	> 29
26	Offsets often produced from axils of leaves and bracts.	Sedum stenopetalum
26	Offsets not formed from axils of leaves and bracts	> 27
27	Sepals connate basally.	Sedum ochroleucum
27	Sepals distinct	> 28
28	Sepals lanceolate or ovate-elliptic.	Sedum villosum
28	Sepals linear to narrowly oblong.	Sedum stelliforme
29	Carpels divergent or stellately spreading in fruit.	Sedum havardii
29	Carpels erect in fruit	> 30
30	Inflorescences (4-)10-27-flowered cymes; pedicels 1-3.5 mm; leaf blades 9.5-15 mm	Sedum cockerellii
30	Inflorescences 2-9-flowered cymes or solitary flowers; pedicels absent or to 1 mm, or pedicels 3-8 mm; leaf blades 3-8 mm	> 31
31	Pedicels absent or to 1 mm.	Sedum niveum
31	Pedicels 3-8 mm.	Sedum villosum
32	Leaves whorled or opposite and decussate (rarely alternate)	> 33
32	Leaves alternate	> 37
33	Leaves usually opposite and decussate (rarely alternate)	> 34
33	Leaves whorled	> 35
34	Petals usually distinct, sometimes connate basally; carpels widely spreading in fruit; leaf blades green or reddish green, not glaucous, suborbiculate to spatulate-obovate or oblong.	Sedum divergens
34	Petals connate basally; carpels erect or ascending in fruit; leaf blades pale green speckled with pink, sometimes pink or red, glaucous, elliptic, ovate-elliptic, oblanceolate, or obovate.	Sedum debile
35	Leaves 4(-5) per whorl, blade linear-elliptic or linear-lanceolate; flowering shoots erect.	Sedum mexicanum
35	Leaves 3(-4) per whorl, blade narrowly rhombic-elliptic to widely lanceolate or linear-lanceolate to linear; flowering shoots ascending, pendulous, or creeping	> 36
36	Leaf blades narrowly rhombic-elliptic to widely lanceolate; flowering shoots creeping or ascending.	Sedum sarmentosum
36	Leaf blades linear-lanceolate to linear; flowering shoots ascending or pendulous.	Sedum lineare
37	Inflorescences paniculate cymes	> 38
37	Inflorescences corymbs, corymbiform cymes, or cymes, sometimes subscorpioid	> 42
38	Flowering shoots glandular-pubescent.	Sedum moranii
38	Flowering shoots glabrous	> 39
39	Subshrubs; leaf blades elliptic-oblanceolate, 40-80 × 13-25 mm; petals widely spreading.	Sedum praealtum
39	Perennial herbs; leaf blades obovate, oblanceolate, oblanceolate-oblong, or spatulate, (4-)12-28(-67) × 4-11(-18) mm; petals erect proximally, spreading or divergent distally	> 40
40	Leaf blade margins white; 300-900 m.	Sedum albomarginatum
40	Leaf blade margins not white; 300-3700 m	> 41
41	Flowering shoots 2-10(-12) cm.	Sedum obtusatum
41	Flowering shoots (6-)10-28 cm.	Sedum oregonense
42	Leaf blades linear or linear-lanceolate to oblong	> 43
42	Leaf blades spatulate, orbiculate to broadly ovate, ovate, obovate, lanceolate, elliptic, elliptic-lanceolate, elliptic-oblong, cuneate, or triangular-ovate	> 46
43	Petals 3-4 mm; leaves usually in 6 rows.	Sedum sexangulare
43	Petals 5-10 mm; leaves on vegetative shoots spirally arranged or alternate, not in rows	> 44
44	Flowering shoots with axillary offsets; leaf blade bases scarious.	Sedum stenopetalum
44	Flowering shoots without axillary offsets; leaf blade bases not scarious	> 45
45	Leaf blades linear-lanceolate; sepals lanceolate, 3-6 mm, densely glandular-pubescent; petals erect or suberect, lanceolate, 8-10 mm.	Sedum ochroleucum
45	Leaf blades linear to oblong; sepals ovate, 2-3(-3.3) mm, glabrous or sparsely glandular-pubescent; petals spreading, oblong, 6-7 mm.	Sedum rupestre
46	Plants not forming rosettes or offsets	> 47
46	Plants forming rosettes, or offsets formed at time of flowering	> 49
47	Plants tufted.	Sedum robertsianum
47	Plants mat-forming	> 48
48	Leaf blades orbiculate to broadly ovate.	Sedum nanifolium
48	Leaf blades triangular-ovate.	Sedum acre
49	Leaf blades obovate, lanceolate, elliptic, elliptic-lanceolate, elliptic-ovate, ovate, elliptic-oblong, or linear	> 50
49	Leaf blades spatulate, oblong-spatulate, or cuneate	> 53
50	Carpels erect in fruit	> 51
50	Carpels divergent in fruit	> 52
51	Leaves not easily detached; petals canary yellow to golden yellow.	Sedum lanceolatum
51	Leaves easily detached; petals deep yellow.	Sedum rupicola
52	Leaf blades linear to elliptic-oblong.	Sedum stenopetalum
52	Leaf blades usually obovate or elliptic, rarely lanceolate.	Sedum borschii
53	Flowering shoots glandular-pubescent.	Sedum moranii
53	Flowering shoots glabrous	> 54
54	Petals widely spreading from short, erect base; filaments yellow.	Sedum spathulifolium
54	Petals basally erect, divergent distally; filaments white, greenish, greenish white, pink, or yellowish	> 55
55	Petals not carinate, pink, pinkish white, or white to yellowish white; leaf blades 10-50 × 6-33 mm, base not spurred.	Sedum laxum
55	Petals carinate, yellow; leaf blades 7-12 × 4.4-9 mm, base short-spurred.	Sedum oreganum