Cirsium crassicaule Jeps.

Slough thistle (en)

Species

Angiosperms > Asterales > Asteraceae > Cirsium

Characteristics

Annuals or biennials, (60–)100–300 cm; taprooted. Stems usually 1, erect, stout, (hollow, 2–10 cm diam. at base), openly branched distally, thinly arachnoid, villous with jointed trichomes, at least proximally. Leaves: blades elliptic to broadly oblanceolate, 15–70 × 30–150+ cm, flat, pinnatifid 1/2–2/3 distance to midvein, larger usually with broad sinuses, lobes broad, few lobed or dentate, main spines 3–8 mm, abaxial faces gray-tomentose, adaxial thinly arachnoid-tomentose, sometimes midveins with jointed trichomes; basal present or withered at flowering, winged-petiolate; principal cauline sessile, progressively reduced distally, bases clasping or short-decurrent 1–2 cm; distal cauline reduced, becoming bractlike, sometimes spinier than proximal. Heads 1–several at branch tips, closely subtended by clustered leafy bracts or not, collectively forming open, corymbiform or paniculiform arrays. Peduncles 0–15 cm. Involucres ovoid to campanulate, 1.5–3 × 1.5–3 cm, ± glabrous. Phyllaries in 5–7 series, weakly unequal, dark green to brownish, lanceolate (outer) to linear (inner), abaxial faces without (or with very obscure) glutinous ridge; outer and middle appressed or apices spreading, at least outer irregularly spiny-fringed, finely serrulate, spines slender, 3–5 mm; apices of inner erect, abaxial faces gray-tomentose, ± twisted. Corollas pale rose-purple (white), 19–26 mm, tubes 9–12 mm, throats 4–6 mm, lobes 5–9 mm; style tips 3.5–4.5 mm. Cypselae dark brown, 5–5.5 mm, collars narrow, ± stramineous; pappi 15–20 mm. 2n = 32.
Life form annual
Growth form herb
Growth support free-standing
Foliage retention deciduous
Sexuality hermaphrodite
Pollination -
Spread -
Mature width (meter) -
Mature height (meter) 1.0 - 3.0
Root system tap-root
Rooting depth (meter) -
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months -
Nitrogen fixer -
Photosynthetic pathway -

Environment

Light 7-9
Soil humidity 5-7
Soil texture 3-4
Soil acidity -
Soil nutriment -
Hardiness (USDA) -

Usage

Uses -
Edible -
Therapeutic use -
Human toxicity -
Animal toxicity -

Cultivation

Mode -
Germination duration (days) 15 - 18
Germination temperacture (C°) 21 - 23
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Distribution

Cirsium crassicaule world distribution map, present in United States of America

Identifiers

LSID urn:lsid:ipni.org:names:58992-2
WFO ID wfo-0000095065
COL ID 5Z92X
BDTFX ID -
INPN ID -
Wikipedia (EN) Link
Wikipedia (FR)

Synonyms

Cirsium crassicaule Carduus crassicaulis