New Mexico thistle, more...
[Carduus inamoenus Greene, more]
40-290 cm; taprooted. Stems
usually 1, erect, thinly gray-tomentose, sometimes ± glabrate; branches few-many, usually from above middle, ascending. Leaves:
blades oblong-elliptic to oblanceolate, 6-35 × 1.5-7 cm, shallowly to deeply pinnatifid, lobes usually rigidly spreading, undivided or with 1-2 pairs of coarse teeth or lobes, main spines 5-15 mm, faces gray-tomentose, sometimes glabrate; basal often present at flowering, winged-petiolate or sessile, bases tapered, spiny-winged; principal cauline sessile, much reduced distally, bases decurrent as spiny wings less than 5 cm; distal much reduced, ± bractlike, sometimes scarcely more than a cluster of long spines. Heads
1-6 (many on large individuals), borne singly or in corymbiform arrays. Peduncles
(2.5-)5-30 cm, bracted. Involucres
shallowly hemispheric or campanulate, 2-3 × 2.5-5 cm, arachnoid to ± loosely tomentose, sometimes glabrous. Phyllaries
in 7-10 series, imbricate to subequal, linear to narrowly lanceolate, abaxial faces with narrow or no glutinous ridge; outer and mid bodies appressed, entire or minutely spinulose, apices deflexed to spreading or ascending, long, flat, spines spreading to reflexed, 4-15 mm; apices of inner erect, often flexuous, flat. Corollas
white to pale lavender or pink, 18-27 mm, tubes 8-14 mm, throats 4-7 mm, lobes 5-9 mm; style tips 4-5 mm. Cypselae
dark brown, 5-6 mm, apical collars not differentiated; pappi
15-20 mm. 2n
= 30 (as C. utahense
), 32; 30 + 1 I. Flowering spring-summer (Mar-Jul). Canyons, slopes, roadsides in deserts, dry grasslands, and arid woodlands dominated by pinyon pines, junipers, oaks, Joshua trees; 300-2100 m; Ariz., Calif., Colo., Nev., N.Mex., Tex., Utah; Mexico (Sonora). Desert thistle is widespread in the Mojave and Sonoran deserts and ranges into the southern Great Basin desert, western Chihuahuan desert, and into adjacent mountains of Utah, southwestern Colorado, Arizona, and New Mexico.
The name Cirsium utahense has been widely applied in the past to plants that are here recognized as C. inamoenum. S. L. Welsh (1983) treated it as a variety of C. neomexicanum. I have examined the type of C. utahense and can find no basis for distinguishing it from C. neomexicanum at any rank. The desert thistle is closely related to C. occidentale.
Plant: Biennial forb (or short-lived perennial herb), to 40-120 cm; stem generally 1, generally simple below; branches few above, ascending, ± white-cobwebby-tomentose, puberulent Leaves: ± persistently gray-tomentose (both surfaces), lighter below; lower 6-35 cm, petioled or tapered to spiny-winged base, oblong-elliptic to oblanceolate, ± lobed, lobes generally rigidly spreading, simple or with 2-4 coarse teeth or secondary lobes, main spines 5-15 mm; middle and upper generally smaller, narrower, decurrent as spiny wings, uppermost well separated, much reduced, ± bract-like, sometimes barely a cluster of long spines INFLORESCENCE: primary inflorescence a head, each resembling a flower; heads discoid, 1-few in open cyme-like clusters (sometimes on short axillary branches); peduncles 2.5-30 cm, leafy; involucres 2-2.5 cm, 2.5-5 cm diam, hemispheric or bell-shaped, ± loosely tomentose, sometimes glabrous; phyllaries linear-lanceolate, entire, sometimes midveins with glandular area, outer and middle spreading to reflexed, spines 4-15 mm, inner with tips ± erect, flat Flowers: corollas 18-27 mm, ± bilateral, white to pale lavender or pink, tube 8-14 mm, slender, throat 4-7 mm, lobes linear, 5-9 mm; anther bases sharply sagittate, tips oblong; style tip with slightly swollen node, appendage (above node) long, cylindric, branches very short Fruit: 5-6 mm, dark brown, ± flattened, ovoid, glabrous; scar slightly angled; pappus 15-20 mm, bristles many, plumose Misc: Canyons, slopes, roadsides; 800-2100 m.; Apr-May References: Kearny & Peebles; Arizona Flora. McDougall; Seed plants of Northern Arizona. ASU specimans