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pasture thistle

melancholy thistle

Habit Biennials or monocarpic perennials, 25–100 cm; sometimes perennating by root sprouts. Perennials, 40–120 cm; runner roots.
Stems

erect, villous with septate trichomes and sometimes thinly arachnoid tomentose;

branches 0–few, distal, ascending.

single, erect, ± arachnoid-tomentose;

branches 0 or few, ascending.

Leaves

blades oblong-elliptic, 5–30+ × 2–10 cm, ± undulate, shallowly to deeply pinnatifid, lobes ovate to broadly triangular, usually separated by broad sinuses, spinose-dentate or lobed, main spines 1.5–7 mm, slender to stout, abaxial faces villous with septate trichomes, at least along veins, sometimes thinly arachnoid, adaxial faces villous with septate trichomes and thinly arachnoid tomentose or subglabrous;

basal often present at flowering, bases tapered;

principal cauline sessile, moderately reduced distally, bases often auriculate-clasping;

distal reduced, similar to proximal.

oblong to broadly lanceolate, 20–40 × 4–8 cm, finely spinulose-dentate or proximal cauline pinnatifid, lobes undivided, finely spinulose-dentate, main spines 1–2 mm, abaxial faces white-tomentose (with non-septate trichomes), adaxial glabrous;

basal present at flowering, petiolate, bases tapered;

cauline sessile, reduced distally, bases clasping, not decurrent;

distal (few, well separated), oblong or linear, the uppermost reduced to linear bracts.

Peduncles

0–15+ cm (above distal leaves), leafy-bracted.

2–10(–30) cm (elevated above distal leaves).

Involucres

broadly cylindric to ovoid, 3.5–5 cm, 2.5–3 cm diam. (appearing much wider and hemispheric to campanulate in pressed specimens), loosely arachnoid on phyllary margins or glabrate.

broadly ovoid, 2–3 × 2–3.5 cm, glabrous or loosely arachnoid.

Corollas

pink to purple (white), 40–60 mm, tubes 20–35 mm, throats 11–15 mm, lobes 7–10 mm;

style tips 3–7 mm.

red-purple, 25–30 mm, tubes 10–23 mm, throats 8–14 mm (noticeably wider than tubes), lobes 7–10 mm;

style tips 4–5 mm.

Phyllaries

in 8–10 series, imbricate, ovate or lanceolate (outer) to lance-linear (inner), abaxial faces with ± prominent glutinous ridge, outer and middle appressed, apices ascending to spreading, spines 1.5–6 mm;

apices of middle and inner narrowed and scabrid-denticulate, innermost spineless, tapered and entire or with expanded, erose-denticulate, flexuous tips.

in 8–10 series, imbricate, green, ovate or lanceolate (outer) to linear-lanceolate (inner), abaxial faces with a prominent elongate glutinous ridge, outer and middle tightly appressed, margins entire, apices with ascending, weak spines 0–1 mm;

apices of inner phyllaries attenuate, flat.

Heads

1–few, borne singly at tips of main stem and branches, often closely subtended by 1–several bracts.

borne singly or less commonly 2–5 in terminal clusters.

Cypselae

stramineous to brown, 3.5–5 mm, apical collars yellow or colored like body;

pappi 35–45 mm.

light brown, 3–5 mm, bodies and apical collars concolorous;

pappi 20–30 mm.

2n

= 30.

= 34.

Cirsium pumilum

Cirsium helenioides

Phenology Flowering summer (Jul–Aug).
Habitat Fjordlands
Elevation 0–50 m (0–200 ft)
Distribution
from FNA
CT; DE; IA; IL; IN; MA; MD; ME; MI; MN; NC; NH; NJ; NY; OH; PA; RI; SC; VA; VT; WI; WV; ON; United States
[WildflowerSearch map]
[BONAP county map]
from USDA
Greenland; Iceland; Europe; Asia
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Flowers of Cirsium pumilum are reportedly sweetly scented.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Cirsium helenioides is one of only two species of the genus that have native populations in the Old World and the flora area. Neither reaches the North American mainland.

The conservation status of Cirsium helenioides is not known; it is known in the flora area only from a single fjord and possibly should be considered of conservation concern.

of conservation concern

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Spines of outer phyllaries stout, 3–6 mm; plants usually with several long branches; leaves usually lobed nearly to the midvein; roots rarely and only slightly tuberous-thickened; cypselae usually 3.5– 4 mm
var. pumilum
1. Spines of outer phyllaries slender, 1.5–3 mm; plants simple or distally with a few short branches; leaves usually shallowly lobed; roots often tuberous-thickened; cypselae usually 4.5–5 mm
var. hillii
Source FNA vol. 19, p. 116. FNA vol. 19, p. 110.
Parent taxa Asteraceae > tribe Cardueae > Cirsium Asteraceae > tribe Cardueae > Cirsium
Sibling taxa
C. altissimum, C. andersonii, C. andrewsii, C. arizonicum, C. arvense, C. barnebyi, C. brevifolium, C. brevistylum, C. canescens, C. carolinianum, C. ciliolatum, C. clavatum, C. crassicaule, C. cymosum, C. discolor, C. douglasii, C. drummondii, C. eatonii, C. edule, C. engelmannii, C. flodmanii, C. foliosum, C. fontinale, C. grahamii, C. helenioides, C. hookerianum, C. horridulum, C. hydrophilum, C. inamoenum, C. joannae, C. kamtschaticum, C. lecontei, C. longistylum, C. mohavense, C. muticum, C. neomexicanum, C. nuttallii, C. occidentale, C. ochrocentrum, C. ownbeyi, C. palustre, C. parryi, C. perplexans, C. pitcheri, C. praeteriens, C. pulcherrimum, C. quercetorum, C. remotifolium, C. repandum, C. rhothophilum, C. rydbergii, C. scariosum, C. texanum, C. tracyi, C. turneri, C. undulatum, C. vinaceum, C. virginianum, C. vulgare, C. wheeleri, C. wrightii
C. altissimum, C. andersonii, C. andrewsii, C. arizonicum, C. arvense, C. barnebyi, C. brevifolium, C. brevistylum, C. canescens, C. carolinianum, C. ciliolatum, C. clavatum, C. crassicaule, C. cymosum, C. discolor, C. douglasii, C. drummondii, C. eatonii, C. edule, C. engelmannii, C. flodmanii, C. foliosum, C. fontinale, C. grahamii, C. hookerianum, C. horridulum, C. hydrophilum, C. inamoenum, C. joannae, C. kamtschaticum, C. lecontei, C. longistylum, C. mohavense, C. muticum, C. neomexicanum, C. nuttallii, C. occidentale, C. ochrocentrum, C. ownbeyi, C. palustre, C. parryi, C. perplexans, C. pitcheri, C. praeteriens, C. pulcherrimum, C. pumilum, C. quercetorum, C. remotifolium, C. repandum, C. rhothophilum, C. rydbergii, C. scariosum, C. texanum, C. tracyi, C. turneri, C. undulatum, C. vinaceum, C. virginianum, C. vulgare, C. wheeleri, C. wrightii
Subordinate taxa
C. pumilum var. hillii, C. pumilum var. pumilum
Synonyms Carduus pumilus Carduus helenioides, C. heterophyllum
Name authority (Nuttall) Sprengel: Syst. Veg. 3: 375. (1826) (Linnaeus) Hill: Hort. Kew., 64. (1768)
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