Cirsium grahamii |
Cirsium repandum |
|
---|---|---|
Graham's thistle |
coastal-plain thistle, sand-Hill thistle |
|
Habit | Biennials, 50–100 cm; taproots slender and fascicles of thick fibrous roots. | Perennials, 20–80 cm; creeping roots deep-seated, sometimes appearing as taprooted biennials. |
Stems | 1, erect, thinly arachnoid and/or puberulent to short-pilose, sometimes ± glabrate; branches 0–4, ascending. |
1–several, spreading to erect, (usually very leafy in distal 1/2), loosely arachnoid, and villous with jointed, multicellular trichomes; branches 0–few from above middle, ascending. |
Leaves | blades oblanceolate to oblong-elliptic, 20–30 × 3–8 cm, spinulose and otherwise entire or coarsely dentate to deeply pinnatifid, lobes entire or coarsely few toothed or lobed, main spines slender, 3–6 mm, abaxial ± persistently gray-tomentose, sometimes pilose along veins, adaxial faces thinly arachnoid and ± glabrate; basal often present at flowering, sessile or narrowly winged-petiolate; principal cauline gradually winged-petiolate or sessile, reduced distally, bases sometimes clasping or short-decurrent; distal cauline ascending, becoming bractlike, narrow, lobed or not. |
linear to oblong or oblanceolate, 6–16 × 1–3.5 cm, unlobed to sinuate-dentate or shallowly pinnatifid, main spines 1–4 mm, fine, faces ± green, shaggy-villous with septate trichomes, abaxial loosely arachnoid when young; basal and proximal cauline usually absent at time of flowering; mid and distal nearly uniform in size or gradually reduced, bases clasping; distalmost cauline ± bractlike. |
Peduncles | 10–30 cm. |
0–2 cm. |
Involucres | hemispheric, 2–3 × 2–4 cm, thinly arachnoid or glabrous. |
ovoid or cylindric to campanulate, 2–4 × 1.5–4 cm, loosely arachnoid, ± glabrate. |
Corollas | deep purple, 22–30 mm, tubes 13–18 mm, throats 4–5 mm, lobes 5–8 mm; style tips 4–4.5 mm. |
light purple, 33–40 mm, tubes 14–15 mm, throats 12–15 mm, lobes 7–9 mm; style tips 4.5–6 mm. |
Phyllaries | in ca. 8 series, imbricate, proximally brownish, distally dark purplish, lanceolate to linear, margins of outer hispidulous-ciliolate, spiny fringed, pinnately spiny or with scarious appendages, abaxial faces with prominent, glutinous ridge; outer and middle appressed or only apices spreading, bodies minutely spinulose-denticulate, spines erect to ascending, 1.5–2.5 mm; apices of inner phyllaries often flexuous, flat, scabridulous. |
in 6–9 series, imbricate, lanceolate (outer) to linear (inner), abaxial faces with glutinous ridge, outer and middle tightly appressed, bodies scabrous or spinulose, spines erect or weakly ascending, 1–4 mm; apices of inner phyllaries long-acuminate, spineless. |
Heads | 1–5. |
1–5, in corymbiform arrays. |
Cypselae | tan with dark speckles to dark purplish brown, 4–5.5 mm, apical collars not differently colored; pappi 13–18 mm. |
light brown, 3.5–4 mm, apical collars yellowish, ca. 0.8 mm; pappi 15–30 mm. |
2n | = 32 (Mexico). |
= 30. |
Cirsium grahamii |
Cirsium repandum |
|
Phenology | Flowering Jul–Sep. | Flowering spring–summer (May–Jul). |
Habitat | Oak woodlands, coniferous forests, meadows, often in damp soil | Sandhills, pine barrens, roadsides |
Elevation | 1400–2600 m (4600–8500 ft) | 0–150 m (0–500 ft) |
Distribution |
AZ; NM; Mexico (Chihuahua, Durango, Sonora)
|
GA; NC; SC; VA
|
Discussion | Cirsium grahamii occurs in the mountains of southeastern Arizona and southwestern New Mexico. It forms hybrid swarms with C. parryi and C. scariosum var. coloradense in the White Mountains of Arizona. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cirsium repandum occurs on the Atlantic coastal plain. R. J. Moore and C. Frankton (1969) suggested that Cirsium repandum originated through ancient hybridization between C. pumilum var. pumilum and C. horridulum. They noted that an artificial hybrid (2n = 32) between C. repandum (2n = 30) and C. horridulum (2n = 34) had a mosaic of features of the parental taxa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 124. | FNA vol. 19, p. 113. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Carduus repandus | |
Name authority | A. Gray: Smithsonian Contr. Knowl. 5(6): 102. (1853) | Michaux: Fl. Bor.-Amer. 2: 89. (1803) |
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