Achyrachaena

Schauer

Index Seminum (Bratislave) 1837: [3]. 1837.

Etymology: Greek achyron, scale, and Latin achaenium, fruit, alluding to cypselae
Treatment appears in FNA Volume 21. Treatment on page 258. Mentioned on page 255.

Annuals, 4–62 cm. Stems erect, branched distally. Leaves mostly cauline; proximal opposite, distal alternate; ± sessile; blades linear, margins entire or toothed, faces hirsute or villous and (distal leaves) sparsely glandular-pubescent. Heads radiate, borne singly or in loose, ± corymbiform arrays. Peduncular bracts: pit-glands, tack-glands, and/or spines 0 at tips. Involucres ± campanulate to cylindric or ellipsoid, 3–12+ mm diam. Phyllaries 3–8 in 1 series (± lance-linear, herbaceous, each fully enveloping a ray ovary, abaxially hirsute or villous and sparsely glandular-pubescent or eglandular). Receptacles flat to convex (setulose), paleate (paleae falling, in 1 series between rays and disc, distinct). Ray-florets 3–8, pistillate, fertile; corollas yellow, turning reddish (lobes ± parallel). Disc-florets 4–35, bisexual and fertile; corollas yellow to reddish, tubes ± equaling narrowly funnelform throats, lobes 5, lance-deltate (anthers ± dark purple; styles glabrous proximal to branches). Ray cypselae (black) obcompressed, clavate (10-ribbed, straight, basal attachments centered, apices beakless, faces glabrous or ± scabrous); pappi 0. Disc cypselae (brown to black) similar to rays (± scabrous); pappi of 10 white, oblong scales (apices obtuse). x = 8.

Distribution

w North America, nw Mexico

Discussion

Species 1.

Selected References

None.

... more about "Achyrachaena"
not tailed +, rounded +  and obtuse +
pale +  and dark +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
umbelliform +, spiciform +, paniculiform +, glomerulate +  and corymbiform +
indeterminate +  and determinate +
Bruce G. Baldwin +  and John L. Strother +
Schauer +
decurrent +
compound +  and simple +
linear to linear-elliptic +
lobed;usually spatulate;oblanceolate +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
yellow +  and reddish +
hairy +  and glabrous +
fusiform +, clavate +, obpyramidal +, terete +, compressed +  and obcompressed +
fertile +  and bisexual +
fertile +  and bisexual +
w North America +  and nw Mexico +
Greek achyron, scale, and Latin achaenium, fruit, alluding to cypselae +
glandular-pubescent +, villous +  and hirsute +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
in loose , more or less corymbiform arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.3 cm3 mm <br />0.003 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
less campanulate;cylindric or ellipsoid +
petiolate +  and sessile +
alternate +  and opposite +
lance-deltate +
dentate to pinnatifid or palmatifid +  and entire +
toothed +  and entire +
2-carpellate +
persistent +
Index Seminum (Bratislave) +
clavate +  and obcompressed +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Achyrachaena +
Asteraceae (tribe Heliantheae) subtribe Madiinae +
cylindric +
toothed +  and entire +
4 cm40 mm <br />0.04 m <br /> (62 cm620 mm <br />0.62 m <br />) +
shrub +  and subshrub +