Aphanostephus riddellii

Torrey & A. Gray

Fl. N. Amer. 2: 189. 1842.

Common names: Riddell’s lazydaisy
Treatment appears in FNA Volume 20. Treatment on page 352. Mentioned on page 351, 353.

Perennials, 10–40 (–50) cm (caudices usually woody, stems 1–5+); vestiture sparsely hispidulous to puberulent, stem hairs spreading to deflexed or antrorse, 0.2–0.5 mm. Phyllary apices long-acuminate. Ray-florets 30–75. Disc-floret corollas: bases indurate, not conspicuously swollen. Cypselae: hairs apically glochidiate; pappi coroniform, minutely ciliate or lacerate, 0.1–0.3 mm. 2n = 10, 20.


Phenology: Flowering Mar–Aug(–Oct).
Habitat: Open sites, often calcareous, often with scrubby oaks
Elevation: 100–500 m

Distribution

V20-812-distribution-map.gif

N.Mex., Tex., Mexico (Coahuila)

Discussion

Aphanostephus riddellii is the only perennial in the genus. The caudex usually is woody, bearing numerous stems. The distal cauline leaves (upper half of stem) usually are linear, the basal and proximal cauline are conspicuously broader, spatulate, and dentate to pinnatifid. In other species, distal leaves usually are more similar to proximal.

Selected References

None.

Lower Taxa

None.
... more about "Aphanostephus riddellii"
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
spiciform +, racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Guy L. Nesom +
Torrey & A. Gray +
swollen +
indurate +
broadly oblanceolate;linear-lanceolate +
rugulose +  and muricate +
barbellulate +  and barbellate +
Riddell’s lazydaisy +
not 2-lipped +  and actinomorphic +
yellow +  and white +
subterete +, 4-angled +  and angular-columnar +
fertile +  and bisexual +
fertile +  and bisexual +
N.Mex. +, Tex. +  and Mexico (Coahuila) +
100–500 m +
glabrous +, strigose +, hirsute +  and hispid +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Open sites, often calcareous, often with scrubby oaks +
glochidiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
depressed-hemispheric +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
petiolate +  and sessile +
cauline +  and basal +
deltate +
dentate to pinnatifid +  and entire +
pinnatifid +  and entire +
2-carpellate +
persistent +
lacerate +, ciliate +  and coroniform +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
Flowering Mar–Aug(–Oct). +
ovatelanceolate +
unequal +  and subequal +
long-acuminate +
Fl. N. Amer. +
bearing subulate enations +, hairy +  and bristly +
setiform +
exalbuminous +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
deflexed +, erect +  and decumbent or ascending +
appendaged +  and truncate +
papillate +  and smooth +
Keerlia de +
Aphanostephus riddellii +
Aphanostephus +
species +
tubular +
sparsely hispidulous +  and puberulent +
40 cm400 mm <br />0.4 m <br /> (50 cm500 mm <br />0.5 m <br />) +
10 cm100 mm <br />0.1 m <br /> (40 cm400 mm <br />0.4 m <br />) +
tree +, shrub +  and subshrub +