Amphipappus

Torrey & A. Gray

Boston J. Nat. Hist. 5: 107. 1845.

Etymology: Greek amphi- , double or two, and pappos, pappus alluding to dimorphic pappi, ray cypselae and disc cypselae
Treatment appears in FNA Volume 20. Treatment on page 186. Mentioned on page 5.

Shrubs, 30–60 cm (rounded). Stems erect (bark whitish), intricately branched, becoming leafless and spinescent, branchlets glabrous or densely, hirtellous. Leaves cauline; alternate (ascending); petiolate to subsessile; blades 1-nerved, obovate to narrowly elliptic, margins entire, faces glabrous or hirtellous, often resinous. Heads radiate (discoid), (2–4) in glomerate, terminal clusters, these in corymbiform arrays. Involucres turbino-cylindric, 4–5.5 × 2–3 mm. Phyllaries 7–12 in 3 series, greenish white, 1-nerved (outer keeled), ovate to elliptic, unequal, thin-indurate, margins not scarious, faces glabrous. Receptacles flat, pitted, epaleate. Ray-florets (0–) 1–2, pistillate, fertile; corollas yellow (laminae slightly longer than involucres). Disc-florets 3–7, functionally staminate; corollas yellow, tubes longer than narrowly funnelform throats (nerves 1, yellow, not resinous), lobes 5, reflexed or coiling back, lanceolate; style-branch appendages triangular (nonfunctional, lacking stigmatic lines). Cypselae (ray) oblongelliptic to obovoid, ± flattened, 2-nerved, faces moderately villous; pappi persistent, of 15–20, stramineous, basally connate, flattened, slender, barbellate, apically attenuate bristles in 1 series (disc bristles longer than ray, sometimes undulate or twisted). x = 9.

Distribution

sw United States

Discussion

Species 1.

Amphipappus is characterized by its low-shrubby, intricately branched habit and corymbiform, glomerate clusters of small, few-flowered heads, functionally staminate disc florets, and pappi of short, barbellate bristles, the fertile ray cypselae with pappi of shorter, flattened bristles. The genus is restricted to the Mojave Desert of California, Nevada, Utah, and Arizona where these states are contiguous.

... more about "Amphipappus"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
Guy L. Nesom +
Torrey & A. Gray +
decurrent +
obovate;narrowly elliptic +
rugulose +  and muricate +
hirtellous +, densely +  and glabrous +
? (?) +  and ? (?) +
not 2-lipped +  and actinomorphic +
beaked +, 2-ribbed +  and 5-ribbed +
flattened +, oblongelliptic +  and obovoid +
fertile +  and bisexual +
sw United States +
Greek amphi- , double or two, and pappos, pappus alluding to dimorphic pappi, ray cypselae and disc cypselae +
resinous +
villous +, glabrous +  and hirtellous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
turbino-cylindric +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
petiolate +  and subsessile +
lanceolate +  and coiling +
2-carpellate +
persistent +
greenish white +
ovate +  and elliptic +
Boston J. Nat. Hist. +
bearing subulate enations +, hairy +  and bristly +
concave;usually flat;conic +
porter1943a +
exalbuminous +
spinescent +, leafless +  and branched +
appendaged +  and truncate +
papillate +  and smooth +
Compositae +
Amphipappus +
Asteraceae tribe Astereae +
perennial +, biennial +  and annual +