Centaurea melitensis |
Centaurea benedicta |
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croix de malte, Maltese knapweed, Maltese star thistle or centaury, Maltese star-thistle, Napa thistle, tocalote |
blessed knapweed, blessed thistle, chardon bénit |
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Habit | Annuals, 10–100 cm, herbage loosely gray-tomentose and villous with jointed multicellular hairs, sometimes minutely scabrous, minutely resin-gland-dotted. | Annuals, to 60 cm. |
Stems | 1–few, few–many branched distally. |
often spreading or prostrate, usually branched throughout, usually reddish, ± loosely tomentose. |
Leaves | basal and proximal cauline petiolate or tapering to base, usually absent at anthesis, blades oblong to oblanceolate, 2–15 cm, margins entire to dentate or pinnately lobed; cauline long-decurrent, blades linear to oblong or oblanceolate, 1–5 cm, entire or dentate. |
mostly cauline, sessile and often short-decurrent or proximal tapering to winged petioles, blades lanceolate to oblanceolate, 6–25 cm, margins coarsely dentate or pinnately lobed, lobes and teeth armed with short, weak spines, faces sparsely to densely hairy with jointed multicellular hairs and slender cobwebby hairs, resin-gland-dotted. |
Involucres | ovoid, 10–15 mm, loosely cobwebby-tomentose or becoming glabrous. |
± spheric, 20–40 mm. |
Florets | many; corollas yellow, those of sterile florets 10–12 mm, slender, inconspicuous, those of fertile florets 10–12 mm. |
many; corollas yellow, those of sterile florets linear, 3-lobed, not exceeding disc corollas, very slender, those of disc florets 19–24 mm. |
Phyllaries | in several series, tightly overlapping, outer ovate with tightly appressed bases and spreading spine tips, inner lanceolate, tipped by pinnately divided spines more than 5 mm. |
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Inner phyllaries | appendages entire, acute or spine-tipped. |
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Heads | disciform, 1–few at branch tips, borne singly or in open leafy corymbiform arrays, sometimes clustered in distal axils, sessile or pedunculate. |
disciform, borne singly, sessile, each subtended by involucre-like cluster of leaf-like bracts. |
Cypselae | dull white or light brown, ca. 2.5 mm, finely hairy; pappi of many white, unequal, stiff bristles 2.5–3 mm. |
cylindric, slightly curved, 8–11 mm, with 20 prominent ribs, tipped by a 10-dentate rim, glabrous, attachment scars lateral; pappi of 2 series of awns, outer 9–10 mm, smooth or ± roughened, inner 2–5 mm, roughened with short spreading hairs. |
Principal | phyllaries: bodies ± stramineous, ovate, appendages purplish, spiny-fringed at base, each tipped by slender spine 5–10 mm. |
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2n | = 24. |
= 22. |
Centaurea melitensis |
Centaurea benedicta |
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Phenology | Flowering mostly spring–summer (Apr–Jul). | Flowering spring–summer (Apr–Aug). |
Habitat | Roadsides, fields, pine-oak woodlands, chaparral, agricultural areas | Roadsides, fields, waste places, sometimes cultivated |
Elevation | 0–1500 m (0–4900 ft) | 0–1300 m (0–4300 ft) |
Distribution |
AL; AZ; CA; GA; ID; IL; MA; MO; MS; NJ; NM; NV; OR; PA; TX; UT; WA; WI; BC; Mexico (Baja California); Europe; Asia; Africa [Widely introduced]
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AL; AR; AZ; CA; CT; FL; GA; IL; MD; NC; NJ; NY; OR; SC; TN; TX; UT; VA; WA; WI; NB; NS; ON; Europe; Asia [Introduced in North America; widely introduced worldwide]
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Discussion | Centaurea melitensis is native to the Mediterranean region. It is listed as a noxious weed in New Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Centaurea benedicta is native to the Mediterranean region and Asia Minor. F. K. Kupicha (1975) recognized two varieties of Cnicus benedictus: var. benedictus and var. kotschyi Boissier. A combination apparently has not been made for var. kotschyi in Centaurea. I have not determined whether one or both races are represented in North American plants of Centaurea benedicta. Blessed thistle is cultivated in many areas of the world as a medicinal herb. The leaves, stems, and flowers are all used in herbal preparations for digestive and liver ailments. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 193. | FNA vol. 19, p. 192. |
Parent taxa | Asteraceae > tribe Cardueae > Centaurea | Asteraceae > tribe Cardueae > Centaurea |
Sibling taxa | ||
Synonyms | Cnicus benedictus | |
Name authority | Linnaeus: Sp. Pl. 2: 917. (1753) | (Linnaeus) Linnaeus: Sp. Pl. ed. 2, 2: 1296. (1763) |
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