Cirsium nuttallii |
Cirsium fontinale |
|||||||||
---|---|---|---|---|---|---|---|---|---|---|
Nuttall's thistle |
fountain thistle |
|||||||||
Habit | Biennials, 20–350 cm; taprooted. | |||||||||
Stems | usually single, erect, glabrous or villous with septate trichomes; branches few–many, ascending. |
1–several, erect, loosely arachnoid-tomentose, glandular-pilose; branches several to many, spreading. |
||||||||
Leaves | blades narrowly to broadly elliptic, (10–)15–60 × (2–)5–15 cm, thin, ± flexible, deeply pinnatifid, lobes narrow, spreading, coarsely dentate or lobed, main spines 2–5 mm, abaxial faces thinly tomentose but often wholly glabrate in age, adaxial glabrous or sparsely villous with septate trichomes; basal often absent at flowering, petioles slender, winged, bases tapered; principal cauline becoming sessile and gradually reduced distally, bases spiny-lobed, sometimes decurrent; distal reduced to linear bracts. |
blades oblanceolate to oblong or elliptic, 20–70 × 5–16 cm, strongly undulate, shallowly to deeply pinnatifid, lobes coarsely toothed or with triangular secondary lobes, main spines 3–15 mm, abaxial faces more densely tomentose, adaxial densely glandular with short, multicellular trichomes and ± tomentose with fine, arachnoid, non-septate trichomes; basal often present at flowering, petiolate; principal cauline well distributed, becoming sessile, gradually reduced distally, bases auriculate-decurrent with broad, spiny-margined wings 3 cm or less; distal cauline leaves progressively reduced, ± bractlike. |
||||||||
Peduncles | 1–15 cm, essentially naked (not overtopped by crowded distal leaves). |
0–7 cm. |
||||||||
Involucres | hemispheric to campanulate, 1.5–2.5 × 1–2.5 cm, thinly arachnoid or glabrate. |
(green to purple), hemispheric or campanulate, 1.5–3 × 2–5 cm, glabrous or puberulent. |
||||||||
Corollas | white to pink, lavender, or purple, 17–25 mm, tubes 5–11 mm, throats 4–7 mm (noticeably wider than tubes), lobes 5–7 mm; style tips 3–4.5 mm. |
white to pinkish or lavender, 14.5–22 mm, tubes 5–8 mm, throats 4.5–9 mm, lobes 3–8 mm; style tips 2.5–4.5 mm. |
||||||||
Phyllaries | in 6–10 series, strongly imbricate, green or brownish, ovate or elliptic (outer) to linear-lanceolate (inner), abaxial faces with narrow glutinous ridge; outer and middle appressed, bodies entire, spines abruptly spreading, slender, 1–2(–3) mm; apices of inner often flexuous, flat, attenuate. |
in 6–10 series, imbricate, ovate to lanceolate, abaxial faces without glutinous ridge; outer and mid bases appressed, short, bodies entire to erose or ciliolate (rarely outer spine-margined), apices spreading to recurved or reflexed, long, dilated, adaxially puberulent, spines 1–6 mm; apices of inner erect or reflexed, flattened or tipped with short spines. |
||||||||
Heads | few–many, in open corymbiform or paniculiform arrays. |
few–many, ± nodding, in paniculiform or corymbiform arrays, bracts leafy or much reduced. |
||||||||
Cypselae | dark brown, 3–4 mm, apical collars stramineous, 0.5 mm; pappi 17–21 mm (longer bristles shorter than corollas). |
brownish, 3.4–5 mm, apical collars tan; pappi 12–15 mm. |
||||||||
Monocarpic | perennials, 50–220 cm; woody tap-rooted caudices with numerous coarse, fibrous lateral roots, sometimes forming new rosettes from root sprouts. |
|||||||||
2n | = 24, 26, 28. |
|||||||||
Cirsium nuttallii |
Cirsium fontinale |
|||||||||
Phenology | Flowering summer (Jun–Aug). | |||||||||
Habitat | Roadsides, ditches, woodlands, usually in damp soil | |||||||||
Elevation | 0–100 m (0–300 ft) | |||||||||
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA
|
c Calif
|
||||||||
Discussion | Cirsium nuttallii occurs on the southern coastal plain from southeastern Virginia to southern Florida and west to eastern Louisiana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 3 (3 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||
Key |
|
|||||||||
Source | FNA vol. 19, p. 119. | FNA vol. 19, p. 161. | ||||||||
Parent taxa | Asteraceae > tribe Cardueae > Cirsium | Asteraceae > tribe Cardueae > Cirsium | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Carduus glaber, Carduus nuttallii | Cnicus fontinalis | ||||||||
Name authority | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 651. (1838) | (Greene) Jepson: Fl. W. Calif., 505. (1901) | ||||||||
Web links |