Chaenactis sect. Acarphaea

(Harvey & A. Gray) A. Gray

Proc. Amer. Acad. Arts 10: 74. 1874.

Basionym: Undefined sect. Acarphaea Harvey & A. Gray Mem. Amer. Acad. Arts, n. s. 4: 98. 1849
Treatment appears in FNA Volume 21. Treatment on page 401. Mentioned on page 411.

Annuals; proximal indument predominantly ± farinose, not arachnoid. Stems usually 1, erect; branches mainly distal. Leaves: largest blades deltate to ± ovate [broadly elliptic], (2–) 3–4-pinnately lobed, not glanddotted. Heads discoid (mostly 3–20+ per stem). Peduncles ascending to erect. Phyllaries: outer acute to acuminate-aristate. Florets: corollas white to pinkish, actinomorphic, ± equal. Cypselae ± terete or compressed; pappi 0, coroniform (of ± 10 scales), or of 4 (–5) [10–16] scales in 1 [2–3] series. x = 8.

Distribution

sw United States, nw Mexico

Discussion

Species 3 (2 in the flora).

Selected References

None.

Key

1 Phyllaries: apices (all or inner) usually reddish, acuminate, aristate, terete; receptacles: paleae (0–)3–10+ (± phyllary-like, apices visible among mature floret buds); leaves: ultimate lobes ± terete; cypselae ± terete; involucres mostly 5–10 mm diam Chaenactis carphoclinia
1 Phyllaries: apices (all) ± green, acute or scarcely acuminate, not aristate, ± plane; receptacles: paleae 0; leaves: ultimate lobes plane or involute; cypselae compressed; involucres mostly 10–25 mm diam > 2
2 Pappi 0 or coroniform (of ± 10 scales, longest 0.1–0.5 mm); involucres mostly 10–15 mm diam.; phyllaries ± densely villous, not or sparsely glandular Chaenactis artemisiifolia
2 Pappi of 10–16 scales in 2–3 subequal series, longest scales 4–6 mm; involucres mostly 20–25 mm diam.; phyllaries ± glandular, not or sparsely villous Chaenactis lacera (see 1 Chaenactis artemisiifolia)
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +, cymiform +  and corymbiform +
indeterminate +  and determinate +
James D. Morefield +
(Harvey & A. Gray) A. Gray +
decurrent +
Undefined sect. Acarphaea +
compound +  and simple +
lobed;ovate;oblanceolate;ovate;oblanceolate;linear;deltate +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
connate +  and distinct +
actinomorphic +
white +  and pinkish +
stipitate-glandular +  and hairy +
compressed +  and terete +
fertile +  and bisexual +
fertile +  and bisexual +
sw United States +  and nw Mexico +
strigose +  and densely sericeous +
scabrellous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
campanulate +  and cylindric +
in more or less cymiform arrays +, singly +  and radiant +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
hemispheric;obconic or broadly cylindric +
lobed +, deltate +  and more or less ovate +
cauline +  and basal +
deltate +  and more or less lanceolate +
dentate to pinnatifid or palmatifid +  and entire +
acute +  and acuminate-aristate +
2-carpellate +
persistent +
coroniform +
ascending +  and erect +
5 +  and 21 +
not arachnoid +  and farinose +
Proc. Amer. Acad. Arts +
bearing subulate enations +, hairy +  and bristly +
knobby;convex;more or less flat +
distinct +
4 +  and 20 +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Undefined (tribe Undefined) subtribe Bahiinae +  and Undefined (tribe Undefined) subtribe Palafoxiinae +
Chaenactis sect. Acarphaea +
Chaenactis +
section +
cylindric +
80 cm800 mm <br />0.8 m <br /> (300 cm3,000 mm <br />3 m <br />) +
1 cm10 mm <br />0.01 m <br /> (80 cm800 mm <br />0.8 m <br />) +
toothed +  and entire +
70 cm700 mm <br />0.7 m <br /> (200 cm2,000 mm <br />2 m <br />) +
5 cm50 mm <br />0.05 m <br /> (70 cm700 mm <br />0.7 m <br />) +
80 cm800 mm <br />0.8 m <br /> (300 cm3,000 mm <br />3 m <br />) +