Silybum

Adanson

Fam. Pl. 2: 116, 605. 1763.

Common names: Milk thistle
Etymology: Greek silybon, a kind of thistle
Treatment appears in FNA Volume 19. Treatment on page 164. Mentioned on page 66, 82, 83.
 TaxonIllustrator 
FNA19 P08 Cirsium scariosum var amer.jpegCirsium scariosum var. americanum
Cirsium vinaceum
Silybum marianum
Saussurea americana
John Myers
John Myers
John Myers
John Myers

Annuals or biennials, taprooted, 15–300 cm, herbage glabrous, puberulent, or slightly tomentose, spiny. Stems erect, usually simple. Leaves basal and cauline; petiolate (basal and proximal cauline) or sessile (distal cauline); blades adaxially variegated, margins dentate and often coarsely pinnately lobed, teeth and lobes spine-tipped, glabrous or puberulent. Heads discoid, borne singly, terminal and in distal axils. (Peduncles with reduced leaflike bracts.) Involucres ovoid to spheric, 15–60 mm diam. Phyllaries many in 4–6 series, unequal, outer and mid with appressed bases and spreading, lanceolate to ovate, spiny-fringed, terminal appendages, at least mid spine-tipped, innermost with erect, flat, entire, spineless apices. Receptacles flat, epaleate, covered with whitish bristles. Florets 25–100+; corollas pink to purple, tubes slender, distally bent, abruptly expanded into short throats, lobes linear; stamen filaments connate, anther bases sharply short-tailed, anther appendages oblong; style-branches: fused portions with slightly swollen subterminal nodes, distally cylindric, distinct portions minute. Cypselae ovoid, slightly compressed, not ribbed, apices with smooth, entire rims, glabrous, basal attachment scars slightly angled; pappi falling in rings, outer of many minutely barbed, basally connate, subulate scales, inner of minute smooth bristles. x = 17.

Distribution

Introduced; Mediterranean region

Discussion

Species 2 (1 in the flora).

Selected References

None.

Lower Taxa

"fine" is not a number.

... more about "Silybum"
short-tailed +
rounded;acute +
scarious +
racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
Adanson +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
10-nerved or 20-nerved +  and rugose +
Milk thistle +
actinomorphic +
pink +  and purple +
compressed +  and ovoid +
fertile +  and bisexual +
Mediterranean region +
Greek silybon, a kind of thistle +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
tomentose +, puberulent +  and glabrous +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
ovoid;spheric +
sessile +  and petiolate +
cauline +  and basal +
puberulent +  and glabrous +
deltate +, usually narrowly triangular +  and more or less linear +
2-carpellate +
persistent +
papillate +  and smooth +
distinct +  and fused +
cylindric +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
subulate +
exalbuminous +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Compositae +
Silybum +
Asteraceae tribe Cardueae +
puberulent +  and glabrous +
expanded +  and slender +
biennial +  and annual +
15 cm150 mm <br />0.15 m <br /> (300 cm3,000 mm <br />3 m <br />) +
tree +, vine +, shrub +  and subshrub +