Trixis

P. Browne

Civ. Nat. Hist. Jamaica, 312, plate 33, fig. 1. 1756.

Common names: Threefold
Etymology: Greek trixos, 3-fold, describing the 3-cleft corolla
Treatment appears in FNA Volume 19. Treatment on page 75. Mentioned on page 12, 14, 59, 70, 71, 73, 76.
 TaxonIllustrator 
FNA19 P01 Hecastocleis shockley.jpegTrixis californica var. californica
Hecastocleis shockleyi
Acourtia runcinata
Acourtia wrightii
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey

Shrubs [herbs], 20–300+ cm (often rhizomatous, stems hairy, hairs gland-tipped and glandless). Leaves cauline; sessile or petiolate; blades elliptic, lanceolate, linear, or linear-lanceolate, bases cuneate, margins dentate or entire, faces (at least abaxial) usually glandular and ± strigose. Heads quasi-radiate (see florets), borne singly or in corymbiform or paniculiform arrays. Involucres ± cylindric, 12–15 mm (subtended by calyculi of 3–7 spreading or ascending bractlets). Phyllaries (reflexed in fruit) in 1–2 series, linear (± keeled), apices acute. Receptacles flat, smooth, hairy, epaleate. Florets 4–25 [–60], bisexual, fertile; corollas yellow (aging white), zygomorphic (2-lipped; outer lip liguliform, lobes 3, lance-deltate, inner lip smaller, lobes ± filiform, recurved); anther basal appendages entire, apical appendages oblong, acute; style-branches relatively short, apices truncate-penicillate. Cypselae subcylindric to fusiform, often ± beaked, ribs 5, faces glandular-hairy; pappi of 60–80+ dull white [tawny], finely barbed bristles. x = 9.

Distribution

North America, Mexico, West Indies, Central America, South America

Discussion

Species ca. 65 (2 in the flora).

Key

1 Leaves usually ascending, almost parallel with stems, stomates on both faces, induments: abaxial faces glandular and sparsely strigose (sometimes only on veins), adaxial faces glandular and strigose to pilose; papilla-like double hairs of cypselae producing mucilage when wetted Trixis californica
1 Leaves usually spreading, stomates on abaxial faces, induments: margins and, sometimes, abaxial midveins with glandless and glandular hairs, otherwise glabrous; papilla-like double hairs of cypselae not producing mucilage when wetted Trixis inula
... more about "Trixis"
truncate-penicillate;acute +
scarious +
acute +  and oblong +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
P. Browne +
cuneate +
compound +  and simple +
linear-lanceolate;linear;linear-lanceolate;linear;lanceolate;elliptic +
ribbed;smooth +
barbellulate +  and smooth +
Threefold +
subcylindric +  and fusiform +
North America +, Mexico +, West Indies +, Central America +  and South America +
Greek trixos, 3-fold, describing the 3-cleft corolla +
glandular-hairy +  and strigose +
pistillate +, staminate +  and neuter +
fertile +  and bisexual +
winged +  and beaked +
dispersed +
in corymbiform or paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
1.2 cm12 mm <br />0.012 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
petiolate +  and sessile +
entire +  and dentate +
pinnatifid +, lobed +  and dentate +
2-carpellate +
persistent +
connate +  and distinct +
unequal +  and subequal +
Civ. Nat. Hist. Jamaica, +
flat;convex +
anderson1972a +
barbellulate +  and smooth +
plumose +, subulate +  and setiform +
exalbuminous +
prostrate +  and ascending +
appendaged +  and truncate +
hairy +  and glabrous +
papillate +
Compositae +
Asteraceae tribe Mutisieae +
perennial +  and annual +