Monoptilon

Torrey & A. Gray

Boston J. Nat. Hist. 5: 106, plate 13, figs. 1–6. 1845.

Common names: Desertstar
Etymology: Greek monos, one, and ptilon, soft feather, alluding to pappus of M. bellidiforme, a solitary plumose bristle
Treatment appears in FNA Volume 20. Treatment on page 210. Mentioned on page 11.
 TaxonIllustrator 
FNA20 P22 Chaetopappa ericoides.jpegChaetopappa ericoides
Chaetopappa asteroides var. asteroides
Monoptilon bellidiforme
Barbara Alongi
Barbara Alongi
Barbara Alongi

Annuals, 1–5 cm, herbage hispido-hirsute (hairs long, white), minutely glandular; taprooted. Stems prostrate to decumbent (radiating from base), simple or branched. Leaves basal and cauline; alternate; petiolate; blades 1-nerved, oblong to oblanceolate-spatulate, margins entire (apices rounded to obtuse). Heads radiate, borne singly (usually immediately subtended and surrounded by distal leaves). Involucres campanulate, 4–6 × 6–7 mm. Phyllaries 10–14 in 1 (–2) series, appressed (purple-tipped), 1-nerved (midnerves raised-indurate, evident only in proximal 1/2; proximally convex, not keeled), linear-lanceolate, equal, margins herbaceous or scarious, faces hirsute. Receptacles flat, pitted, epaleate. Ray-florets 12–21, pistillate, fertile; corollas white or rose or purple-tinged (strongly coiling). Disc-florets 28–40, bisexual, fertile; corollas yellow (with prominent orange veins), tubes much shorter than narrowly tubular-funnelform, lobes 5, reflexed, lanceolate; style-branch appendages obtuse to truncate. Cypselae (brownish) obovoid, compressed, 2-ribbed, faces sparsely strigose; pappi persistent, in (1–) 2 series, short-toothed cups plus 1 apically plumose bristle or 8–15 inner, tawny white, barbellate, apically attenuate bristles plus outer of short, laciniate paleae. x = 8.

Distribution

sw United States, n Mexico

Discussion

Species 2 (2 in the flora).

Both species of Monoptilon are decumbent to prostrate, hispid annuals with campanulate involucres, white coiling rays, obovoid compressed cypselae, and chromosome number of 2n = 16. The genus was placed by G. L. Nesom (1994) as sister to Chaetopappa.

Selected References

None.

Key

1 Stems yellow-green; phyllary margins herbaceous; disc corollas loosely strigose proximally; pappi scarious cups 0.1–0.4 mm plus 1 apically plumose bristle usually equaling disc corollas Monoptilon bellidiforme
1 Stems often prominently reddish purple; phyllary margins proximally with sharply delimited, white-scarious portions, lacerate-ciliate at base; disc corollas glabrous or nearly so; pappi outer crowns of paleae or narrow squamellae 0.5–1 mm plus 8–15 barbellate inner bristles, length 1/3 – 1/2 disc corollas Monoptilon bellioides
... more about "Monoptilon"
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 +
decurrent +
oblong;oblanceolate-spatulate +
rugulose +  and muricate +
barbellulate +  and barbellate +
Desertstar +
not 2-lipped +  and actinomorphic +
yellow +, purple-tinged +, rose +  and white +
8 +  and 15 +
short-toothed +
compressed +  and obovoid +
fertile +  and bisexual +
fertile +  and bisexual +
sw United States +  and n Mexico +
Greek monos, one, and ptilon, soft feather, alluding to pappus of M. bellidiforme, a solitary plumose bristle +
strigose +  and hirsute +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
heterogamous +  and homogamous +
hispido-hirsute +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
campanulate +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
cauline +  and basal +
lanceolate +
scarious +  and herbaceous +
2-carpellate +
laciniate +
persistent +
linear-lanceolate +
Boston J. Nat. Hist. +
bearing subulate enations +, hairy +  and bristly +
concave;usually flat;conic +
exalbuminous +
branched +  and simple +
prostrate +  and decumbent +
prostrate +  and ascending +
obtuse +  and truncate +
appendaged +  and truncate +
papillate +  and smooth +
Compositae +
Monoptilon +
Asteraceae tribe Astereae +
much shorter than narrowly tubular-funnelform +
1 cm10 mm <br />0.01 m <br /> (5 cm50 mm <br />0.05 m <br />) +
tree +, shrub +  and subshrub +