Layia pentachaeta

A. Gray in War Department [U.S.]

in War Department [U.S.], Pacif. Railr. Rep. 4(5): 108. 1857.

Endemic
Treatment appears in FNA Volume 21. Treatment on page 266. Mentioned on page 263, 264.

Plants 5–100 cm (self-incompatible); glandular, strongly lemon or acrid-scented. Stems not purple-streaked. Leaf-blades oblanceolate or lanceolate to linear, 6–110 mm, margins (basal leaves) 1–2-pinnatifid. Involucres ± hemispheric, 5–12 × 2–12+ mm. Phyllaries 4–14, apices shorter or longer than folded bases. Paleae in 1 series between ray and disc-florets. Ray-florets 3–14; laminae yellow or white, 3–26 mm. Disc-florets 7–120+; corollas 3–6 mm; anthers yellow to brownish. Ray cypselae glabrous. Disc pappi 0 or of 1–22 whitish, ± equal, setiform scales 1.5–3.5 mm, each proximally plumose, seldom adaxially woolly.

Discussion

Subspecies 2 (2 in the flora).

Molecular phylogenetic data have indicated that Layia pentachaeta is closely related to L. glandulosa and L. discoidea (B. G. Baldwin, unpubl.). Distributions of L. pentachaeta and L. glandulosa overlap broadly; the two species occur in different habitats and natural hybridization has been rarely detected (first-generation hybrids are of low to moderate fertility; J. Clausen 1951).

Selected References

None.

Key

1 Ray corollas yellow Layia pentachaeta subsp. pentachaeta
1 Ray corollas white Layia pentachaeta subsp. albida
... more about "Layia pentachaeta"
not tailed +, rounded +  and obtuse +
yellow +  and brownish +
pale +  and dark +
connate +  and distinct +
shorter or longer +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
umbelliform +, spiciform +, paniculiform +, glomerulate +  and corymbiform +
indeterminate +  and determinate +
Bruce G. Baldwin +, Susan J. Bainbridge +  and John L. Strother +
A. Gray in War Department [U.S.] +
decurrent +
0.6 cm6 mm <br />0.006 m <br /> (11 cm110 mm <br />0.11 m <br />) +
lanceolate +  and linear +
compound +  and simple +
linear to linear-elliptic +
1-2-pinnatifid;oblanceolate;linear +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
yellow +, bicolored +, white +  and cream +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
hairy +  and glabrous +
fusiform +, clavate +, obpyramidal +, terete +, compressed +  and obcompressed +
fertile +  and bisexual +
fertile +  and bisexual +
hirsute +  and strigose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
in more or less corymbiform arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.2 cm2 mm <br />0.002 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
hemispheric +
0.2 cm2 mm <br />0.002 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
white +  and yellow +
0.3 cm3 mm <br />0.003 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
petiolate +  and sessile +
alternate +  and opposite +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
1-2-pinnatifid +
2-carpellate +
persistent +
of 1 +  and 32 elliptic +
subulate +, setiform +, ovate +  and lance-attenuate +
4 +  and 14 +
alternate +  and opposite +
in War Department [U.S.], Pacif. Railr. Rep. +
clavate +  and obcompressed +
flat;convex +
1 +  and 22 +
setiform +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
exalbuminous +
not purple-streaked +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Layia pentachaeta +
species +
cylindric +
entire +  and toothed +
60 cm600 mm <br />0.6 m <br /> (130 cm1,300 mm <br />1.3 m <br />) +
2 cm20 mm <br />0.02 m <br /> (60 cm600 mm <br />0.6 m <br />) +
acrid-scented +