Herbs, perennial, sometimes from bulbs; bulb coat membranous or fibrous-reticulate. Stems scapelike or leafy, simple or branched, glabrous, often glaucous; bulblets sometimes borne in leaf axils. Leaves sessile; basal persistent or withering by flowering, solitary, blade base sometimes attenuate and petiolelike; cauline 0–several, sometimes proximalmost appearing as basal, reduced. Inflorescences monochasiate or ± umbellate, 1–many-flowered, bracteate. Flowers: perianth globose to broadly campanulate; sepals 3, distinct, ovate to lanceolate, usually petaloid and glabrous; petals 3, distinct, usually longer and broader than sepals, sometimes clawed, usually hairy adaxially, bearing adaxial gland near base, often spotted to ± patterned; filaments widened at base; anthers usually basifixed or pseudobasifixed, linear to oblong; ovary superior; style absent; stigmas 3. Fruits capsular, 3-locular, 3-angled or -winged, linear, oblong, or globular, dehiscence septicidal. Seeds many, in 2 rows per locule, irregular or flat, coat usually hexagonally reticulate.

Distribution

w North America, Central America.

Discussion

Species ca. 70 (56 in the flora).

Many species of Calochortus are in cultivation. Bulbs of some species were eaten by Native Americans. Petal shape, gland shape, and pubescence are exceedingly variable in many taxa but often are important in identifying species.

As part of a phylogenetic analysis of relationships within the Liliales, T. B. Patterson (1998) studied variation in noncoding cpDNA sequences throughout Calochortus. He resolved seven main clades that are geographically and ecologically strongly cohesive, including the mariposas of dry grasslands and semideserts, the star-tulips of wet meadows, the cat’s ears of montane woodlands, and the fairy lanterns of closed forests. Patterson suggested that this pattern of relationships is the result of highly localized speciation within the genus.

Selected References

Buxbaum, F. 1958. Der morphologische Typus und die systematische Stellung der Gattung Calochortus. Beitr. Biol. Pflanzen 34: 405–452.

Ness, B. D. 1989. Seed morphology and taxonomic relationships in Calochortus (Liliaceae). Syst. Bot. 14: 495–505.

Ownbey, M. 1940. A monograph of the genus Calochortus. Ann. Missouri Bot. Gard. 27: 371–560.

Ownbey, M. 1969. Calochortus. Univ. Wash. Publ. Bot. 17: 765–779.

Lower Taxa

Calochortus albus, Calochortus amabilis, Calochortus ambiguus, Calochortus amoenus, Calochortus apiculatus, Calochortus argillosus, Calochortus aureus, Calochortus bruneaunis, Calochortus catalinae, Calochortus clavatus, Calochortus coeruleus, Calochortus concolor, Calochortus coxii, Calochortus dunnii, Calochortus elegans, Calochortus eurycarpus, Calochortus excavatus, Calochortus flexuosus, Calochortus greenei, Calochortus gunnisonii, Calochortus howellii, Calochortus indecorus, Calochortus invenustus, Calochortus kennedyi, Calochortus leichtlinii, Calochortus longebarbatus, Calochortus luteus, Calochortus lyallii, Calochortus macrocarpus, Calochortus minimus, Calochortus monanthus, Calochortus monophyllus, Calochortus nitidus, Calochortus nudus, Calochortus nuttallii, Calochortus obispoensis, Calochortus palmeri, Calochortus panamintensis, Calochortus persistens, Calochortus plummerae, Calochortus pulchellus, Calochortus raichei, Calochortus simulans, Calochortus splendens, Calochortus striatus, Calochortus subalpinus, Calochortus superbus, Calochortus tiburonensis, Calochortus tolmiei, Calochortus umbellatus, Calochortus umpquaensis, Calochortus uniflorus, Calochortus venustus, Calochortus vestae, Calochortus weedii, Calochortus westonii

Key

1	Flowers nodding; perianth closed, globular to oblong.	> 2
1	Flowers erect, occasionally spreading; perianth open, usually campanulate.	> 6
2	Petals white, pink, or rose.	> 3
2	Petals yellow.	> 4
3	Sepals spreading; proximal petal gland membranes ± equal to petal width; petals rose.	Calochortus amoenus
3	Sepals appressed to petals; proximal petal gland membranes 1/3–2/3 petal width; petals usually white to pink.	Calochortus albus
4	Stems usually not branching distal to base, 1–10 dm; petals with adaxial surface moderately hairy; leaves and stems conspicuously glaucous.	Calochortus raichei
4	Stems usually branching distal to base, 1–5 dm; petals with adaxial surface glabrous or sparsely hairy; leaves and stems not or slightly glaucous.	> 5
5	Leaves and stems slightly glaucous; petals deep yellow, adaxial surface glabrous or with a few hairs near gland.	Calochortus amabilis
5	Leaves and stems not glaucous; petals pale yellow, adaxial surface glabrous or sparsely hairy.	Calochortus pulchellus
6	Capsules nodding; perianth usually not conspicuously marked.	> 7
6	Capsules erect; perianth usually conspicuously marked.	> 21
7	Adaxial petal surface glabrous or sparsely hairy.	> 8
7	Adaxial petal surfaces densely hairy.	> 11
8	Cauline leaves usually absent.	Calochortus minimus
8	Cauline leaves usually present.	> 9
9	Stems shorter than 5 (10) cm, bearing bulblets near base.	Calochortus uniflorus
9	Stems 8–25 cm, not bearing bulblets.	> 10
10	Petals white to pale pink; c California.	Calochortus umbellatus
10	Petals bright lavender; s Oregon.	Calochortus indecorus
11	Petals deep yellow.	Calochortus monophyllus
11	Petals light green, white, pink, purple, or blue.	> 12
12	Petal margins slightly ciliate or fringed, entire adaxial surface hairy or papillose (except Calochortus elegans, hairy only distal to gland).	> 13
12	Petal margins conspicuously ciliate or fringed, adaxial surface hairy only distal to gland.	> 18
13	Stems usually branching, with bractlike cauline leaf.	Calochortus tolmiei
13	Stems usually simple, often scapelike.	> 14
14	Petal glands nearly round.	Calochortus apiculatus
14	Petal glands lunate or transversely oblong.	> 15
15	Adaxial leaf surface hairy or papillose; Oregon.	> 16
15	Adaxial leaf surface glabrous; widespread.	> 17
16	Petal glands deeply depressed, surrounded by yellow hairs, reddish striations from petal base to gland.	Calochortus coxii
16	Petal glands only slightly depressed, hairs distal to gland not yellow, often surrounded by lime green coloration and purple striations.	Calochortus umpquaensis
17	Distal petal gland membranes absent; sepals without basal glandular blotch; nw United States.	Calochortus elegans
17	Distal petal gland membranes present; sepals with basal glandular blotch; high elevations in Cascade Mountains.	Calochortus subalpinus
18	Petals pink to light purplish.	Calochortus persistens
18	Petals light green, white, or light blue.	> 19
19	Petals light green to white, usually with purple crescent distal to gland.	Calochortus elegans
19	Petals white to light blue, purple crescent absent.	> 20
20	Petals obovate, apex acuminate, margins ciliate to apex.	Calochortus coeruleus
20	Petals lanceolate, apex acute, ciliate only on margins	Calochortus westonii
21	Basal leaves usually persistent at flowering.	> 22
21	Basal leaves usually withering by flowering.	> 31
22	Petals yellow or yellow-green.	> 23
22	Petals white, cream, pink, lavender, or purple, not flecked or streaked purple-brown.	> 24
23	Petals deep yellow, streaked red-brown proximally.	Calochortus luteus
23	Petals light yellow-green, flecked and streaked purple-brown.	Calochortus tiburonensis
24	Petals with longitudinal green stripe on adaxial surface.	Calochortus excavatus
24	Petals without longitudinal green stripe on adaxial surface.	> 25
25	Adaxial petal surface with purple crescent or blotch.	> 26
25	Adaxial petal surface without purple crescent or blotch.	> 29
26	Petals pink or lavender.	> 27
26	Petals whitish or purplish.	> 28
27	Proximal stem internodes very short; stems with bulblet in axil of cauline leaf at or below ground surface; petals light pink to ± lavender.	Calochortus longebarbatus
27	Proximal stem internodes elongate, cauline leaf ca. halfway up stem; stems rarely with bulblet; petals lavender.	Calochortus nitidus
28	Petals obovate, cuneate at base, with median red-purple blotch.	Calochortus eurycarpus
28	Petals ovate to lanceolate, conspicuously clawed, with median red-purple crescent.	Calochortus lyallii
29	Adaxial leaf surface pubescent; petals yellowish white, with purplish hairs toward base; gland with distally branching hairs.	Calochortus howellii
29	Adaxial leaf surface glabrous; petals pale lavender or purplish, without purple hairs at base; gland with ciliate membranes.	> 30
30	Abaxial petal surface with dark purple crescent; glands deeply depressed; dry soils and slopes	Calochortus greenei
30	Abaxial petal surface without dark purple crescent; glands not deeply depressed; moist meadows and lake margins.	Calochortus nudus
31	Petal glands ± glabrous, surrounded by dense, obscuring hairs; bulb coat fibrous-reticulate.	> 32
31	Petal glands hairy; bulb coat, when present, membranous.	> 34
32	Petals pale pink to rose.	Calochortus plummerae
32	Petals cream, yellow to deep orange, purplish, or red-brown.	> 33
33	Petals broadly cuneate or obovate, apex usually without hairy tufts.	Calochortus weedii
33	Petals oblong-ovate, tipped purple-brown, apex with hairy tufts.	Calochortus obispoensis
34	Petal gland ± round, depressed, sometimes deeply so, surrounded by conspicuously fringed membrane.	> 35
34	Petal glands not simultaneously round, depressed, and surrounded by fringed membrane (but sometimes one of these).	> 43
35	Petals yellow or orange to red; stems twisted.	Calochortus kennedyi
35	Petals yellow to gold, white, or lavender, usually tinged with lilac; stems not twisted.	> 36
36	Abaxial petal surface without longitudinal green stripe.	> 37
36	Abaxial petal surface with longitudinal green stripe.	> 40
37	Petals lemon yellow to gold; sepals usually with red to brown blotch at base.	> 38
37	Petals white with reddish brown or purple band or blotch distal to gland, or lemon yellow with maroon blotch distal to gland.	> 39
38	Perianth cup-shaped; stems flexuous; petal glands covered with branching hairs and surrounded by club-shaped hairs.	Calochortus clavatus
38	Perianth campanulate; stems not flexuous; petal glands covered with slender, unbranched hairs and surrounded by a few long hairs.	Calochortus concolor
39	Petals white, tinged with lilac or infrequently magenta; e Nevada and n Arizona north through Utah to e Idaho.	Calochortus nuttallii
39	Petals lemon yellow; n Arizona to se Utah.	Calochortus aureus
40	Petals lavender; bracts 3–8 cm; anthers red-brown.	Calochortus excavatus
40	Petals white, white tinged with lilac, or purplish; bracts 2–5 cm; anthers yellow, maroon, blue, purple, or red.	> 41
41	Sepals without dark purple or red blotch near base; petals cuneate to obovate.	Calochortus invenustus
41	Sepals with dark purple or red blotch near base; petals narrowly obovate.	> 42
42	Petals with red or purple crescent distal to gland, glands surrounded by yellow border.	Calochortus bruneaunis
42	Petals without red or purple crescent distal to gland, glands surrounded by red or purple border.	Calochortus panamintensis
43	Plants rarely bulbose.	> 44
43	Plants usually bulbose.	> 47
44	Petals with conspicuous purple striping, never spotted.	Calochortus striatus
44	Petals spotted, not conspicuously striped.	> 45
45	Stems twining or straggling; each perianth member with transverse yellow bands.	Calochortus flexuosus
45	Stems ± straight; perianth members without transverse yellow bands.	> 46
46	Petals lavender to deep purple, usually with purple blotch at base.	Calochortus splendens
46	Petals white, usually flushed pink, with red-brown blotch distal to gland.	Calochortus dunnii
47	Petal glands ± ovate, longitudinally oblong, or ± round.	> 48
47	Petal glands ± arched, transversely oblong, lunate, doubly lunate, ± triangular, or ± square.	> 51
48	Anthers sagittate.	Calochortus leichtlinii
48	Anthers not sagittate.	> 49
49	Capsules narrow-oblong, rounded in cross section; stems ± flexuous.	Calochortus catalinae
49	Capsules linear, angled in cross section; stems straight.	> 50
50	Sepals and petals ca. 4–5 cm; petal gland hairs slender, not branching.	Calochortus monanthus
50	Sepals and petals ca. 2–3 cm; petal gland hairs thick, distally knobbed.	Calochortus palmeri
51	Petal glands triangular-sagittate.	Calochortus macrocarpus
51	Petal glands ± arched, transversely oblong, lunate, doubly lunate, or ± square.	> 52
52	Petal glands ± square.	> 53
52	Petal glands arched, transversely oblong, ± lunate, or doubly lunate.	> 54
53	Petal glands in lower middle of petal, not surrounded by red blotch.	Calochortus venustus
53	Petal glands nearly adjacent to petal base, surrounded by red blotch.	Calochortus simulans
54	Petal glands ± doubly lunate.	Calochortus vestae
54	Petal glands ± lunate to transversely oblong.	> 55
55	Capsules lanceoloid; coastal.	Calochortus argillosus
55	Capsules linear or linear-oblong; inland.	> 56
56	Petal glands round to lunate.	Calochortus ambiguus
56	Petal glands transversely oblong, chevron-shaped, or weakly lunate, never round.	> 57
57	Petal glands strongly chevron-shaped to weakly lunate; petals with median brown or purple blotch surrounded by bright yellow zone; California.	Calochortus superbus
57	Petal glands transversely oblong; petals with transverse purple band distal to gland, and purple blotch on claw; Rocky Mountains, se Arizona, w New Mexico.	Calochortus gunnisonii