Cynara cardunculus subsp. flavescens |
Cynara |
|
---|---|---|
cardoon |
cynara |
|
Habit | Annuals or perennials, 50–250 cm, herbage ± arachnoid-tomentose. | |
Stems | ± erect, simple or branched, (leafy), stout. |
|
Leaves | armed with spines 1–3 cm. |
basal and cauline; petiolate (basal and proximal cauline) or sessile (distal cauline); blade margins 1–3-pinnately lobed or divided, sometimes essentially compound, spineless or with slender to very stout marginal spines, cauline progressively smaller and less divided distally, distalmost bractlike, abaxial faces pilose to densely gray-tomentose, adaxial glabrous or thinly tomentose, sometimes glandular. |
Involucres | hemispheric or ovoid, sometimes constricted distally, 5–15 cm diam. |
|
Receptacles | concave to flat or convex, epaleate, densely long-bristly. |
|
Florets | many; corollas white, blue, or purple, tubes very slender, throats abruptly expanded, cylindric, lobes linear; anther bases long-sagittate, fringed, apical appendages oblong; style branches: fused portions long, cylindric, minutely papillate, distinct portions minute. |
|
Phyllaries | many in 5–8+ series, unequal; outer lanceolate to broadly ovate, leathery, margins entire, with appressed bases and spreading apical appendages, acute to broadly obtuse or truncate, spine-tipped or spineless; inner scarious. |
|
Heads | discoid, borne singly or in few-headed, terminal, cymiform arrays. |
|
Cypselae | ± cylindric to obpyramidal, ± 4-angled, finely ribbed, sometimes ± flattened, glabrous, apices truncate, smooth, attachment scars basal; pappi falling in rings of many (white or brownish), stiff bristles in 3–7 series, connate at bases, plumose proximally, often merely barbed distally. |
|
Middle | phyllaries acute to short-acuminate at apex with point 10–21 mm and spine tip 2–5(–6) mm, distal margins with prominent yellowish margins 0.5–1+ mm. |
|
x | = 34. |
|
Cynara cardunculus subsp. flavescens |
Cynara |
|
Phenology | Flowering spring–summer (Apr–Jul). | |
Habitat | Disturbed areas in grasslands, coastal scrub, chaparral, riparian habitats, fallow fields, roadsides | |
Elevation | 0–500 m (0–1600 ft) | |
Distribution |
CA; w Mediterranean region; Macaronesia [Introduced in North America] |
Mediterranean region; Macaronesia; w Asia [Introduced in North America] |
Discussion | Artichoke thistle is a noxious weed that tends to spread aggressively in overgrazed range lands and may invade undisturbed natural vegetation as well. Dense infestations form pure stands, sometimes several hec-tares in extent. The long, needlelike spines deter herbivores and the large rosettes suppress the growth of other plants. Vigorous root sprouts can develop from fragments of the deep taproots left in the soil by cultivation or mechanical clearing. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 8 (1 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 90. | FNA vol. 19, p. 89. |
Parent taxa | ||
Sibling taxa | ||
Subordinate taxa | ||
Name authority | Wiklund: Bot. J. Linn. Soc. 109: 120, fig. 15A–D, F–J. (1992) | Linnaeus: Sp. Pl. 2: 827. (1753): Gen. Pl. ed. 5, 359. (1754) |
Web links |
|