10.
Madia sativa
Molina, Sag. Stor. Nat. Chili. 136. 1782.
Chile tarweed
Madia capitata
Nuttall
Plants
(0.3—)35—100(—240) cm, self-compatible (heads not showy).
Stems
hirsute and glandular-pubescent, glands yellowish, purple, or black, lateral branches rarely surpassing main stems.
Leaf blades
broadly lanceolate to linear-oblong or linear, 2—18 cm × 3—18(—29) mm.
Heads
in usually crowded, paniculiform, racemiform, or spiciform arrays.
Involucres
ovoid to urceolate, 6—16 mm.
Phyllaries
hirsute and glandular-pubescent, glands yellowish, purple, or black, apices erect or ± reflexed, flat.
Paleae
mostly persistent, connate
1
/2+ their lengths.
Ray florets
(5—)8—13; corollas greenish yellow or sometimes purplish red abaxially or throughout, laminae 1.5—4 mm.
Disc florets
11—14, bisexual, fertile; corollas 2—5 mm, pubescent; anthers ± dark purple.
Ray cypselae
black or brown, sometimes mottled, dull, compressed, beakless.
Disc cypselae
similar.
2
n
= 32.
Flowering May—Oct. Grasslands, openings in shrublands and woods, disturbed sites, stream banks, roadsides; 0—1000 m; B.C., Calif., Oreg., Wash.; South America (Argentina, Chile); Pacific Islands (Hawaii, probably introduced).
In North America,
Madia sativa
occurs on the Pacific Coast from California to British Columbia, sporadically in coastal ranges, and rarely eastward. Reports of
M. sativa
from Ontario and Quebec and from Alaska, Connecticut, Georgia, Idaho, Indiana, Iowa, Maine, Maryland, Massachusetts, New York, North Carolina, Pennsylvania, Vermont, and Wisconsin are putative waifs or misidentified
M. glomerata
. Molecular data and greenhouse studies have indicated that plants referable to
M. capitata
and
M. sativa
in California are not distinct (B. G. Baldwin, unpubl.). Sampled populations of
M. sativa
(including
M. capitata
) from California are somewhat divergent in DNA sequences from sampled Chilean populations, in apparent conflict with earlier suggestions that
M. sativa
was recently introduced to North America from South America by Europeans (Baldwin, unpubl.).
Madia sativa
has been cultivated for seed-oil in South America, Europe, Africa, and Asia Minor (E. Zardini 1992).
