Helianthus praecox subsp. hirtus

(Heiser) Heiser

Mem. Torrey Bot. Club 22(3): 54. 1969.

Common names: Dimmit sunflower
EndemicConservation concern
Basionym: Helianthus debilis subsp. hirtus Heiser Madroño 13: 162, fig. 7. 1956
Treatment appears in FNA Volume 21. Treatment on page 152.

Stems erect, branches ascending, densely hirsute or hispid-hirsute. Leaves (larger) 8–9 cm. Peduncles (25–) 30–40 cm. Phyllary apices short-attenuate. Paleae: middle teeth white-villous (“bearded”). Rays 14–16.2n = 34.


Phenology: Flowering early summer–fall.
Habitat: Sandy soils
Elevation: 50–100+ m

Discussion

Of conservation concern.

Subspecies hirtus is known from only a single population, near Carrizo Springs; it is genetically distinct from the two other subspecies (L. H. Rieseberg and M. F. Doyle 1989)

Selected References

None.

Lower Taxa

None.
hispidulous +  and hispid-hirsute +
not tailed +, rounded +  and obtuse +
pale +  and dark +
connate +  and distinct +
short-attenuate;short-acuminate +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
spiciform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Edward E. Schilling +
(Heiser) Heiser +
cuneate +  and cordate +
Helianthus debilis subsp. hirtus +
3 cm30 mm <br />0.03 m <br /> (9 cm90 mm <br />0.09 m <br />) +
deltate;ovate +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
hispid-hirsute +  and hirsute +
barbellulate +  and barbellate +
Dimmit sunflower +
reddish +  and yellow +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
compressed +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
50–100+ m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sandy soils +
in more or less corymbiform , paniculiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
1.3 cm13 mm <br />0.013 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
hemispheric +
1.6 cm16 mm <br />0.016 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
sessile +  and petiolate +
8 cm80 mm <br />0.08 m <br /> (?) +  and 9 cm90 mm <br />0.09 m <br /> (?) +
triangular +
serrate +  and serrulate +
2-carpellate +
3-toothed +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
persistent +
coroniform +
25 cm250 mm <br />0.25 m <br /> (30 cm300 mm <br />0.3 m <br />) +
30 cm300 mm <br />0.3 m <br /> (40 cm400 mm <br />0.4 m <br />) +
5 cm50 mm <br />0.05 m <br /> (9 cm90 mm <br />0.09 m <br />) +
Flowering early summer–fall. +
short-attenuate +
0.9 cm9 mm <br />0.009 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
30 +  and 39 +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Mem. Torrey Bot. Club +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
aristate +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
exalbuminous +
Endemic +  and Conservation concern +
hirsute +, hispid-hirsute +  and hispid +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus praecox subsp. hirtus +
Helianthus praecox +
subspecies +
campanulate +
toothed +  and entire +
300 cm3,000 mm <br />3 m <br /> (500 cm5,000 mm <br />5 m <br />) +
40 cm400 mm <br />0.4 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
shrub +  and subshrub +