Poteridium annuum

(Nuttall) Spach

Ann. Sci. Nat., Bot., sér. 3, 5: 43. 1846.

Common names: Prairie burnet
EndemicIllustrated
Basionym: Poterium annuum Nuttall in W. J. Hooker, Fl. Bor.-Amer. 1: 198. 1832
Synonyms: Sanguisorba annua (Nuttall) Nuttall
Treatment appears in FNA Volume 9. Treatment on page 320.

Plants winter-annual or biennial, glabrous; taproots 1–4 (–6) dm. Stamens (2 or) 4. Fruits: hypanthia ridges extended into thin wings, 0.5 mm wide; sepals tuberculose-thickened proximally.


Phenology: Flowering Mar–Jun; fruiting Apr–Jul.
Habitat: Sandy and rocky soil, prairies, oak savannas, oak woodlands, disturbed areas (pastures, roadsides), often locally moister sites
Elevation: 0–500 m

Distribution

V9 521-distribution-map.jpg

Ont., Ark., Iowa, Kans., N.Y., Okla., S.C., Tex.

Discussion

The eastern records (Ontario, Iowa, Massachusetts, New York, and South Carolina) all appear to represent adventives or non-persistent waifs. A record from Maryland (J. B. S. Norton and R. G. Brown 1946) is plausible; no specimen is known to the author.

Selected References

None.

Lower Taxa

None.
... more about "Poteridium annuum"
Alan S. Weakley +
(Nuttall) Spach +
compound +  and simple +
opposite +  and alternate +
Poterium annuum +
oblanceolate +  and obovate +
2 cm20 mm <br />0.02 m <br /> (7 cm70 mm <br />0.07 m <br />) +
free +  and distinct +
Prairie burnet +
Ont. +, Ark. +, Iowa +, Kans. +, N.Y. +, Okla. +, S.C. +  and Tex. +
not +  and aggregated +
0–500 m +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Sandy and rocky soil, prairies, oak savannas, oak woodlands, disturbed areas (pastures, roadsides), often locally moister sites +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
axillary +  and distal +
crassinucellate +
deciduous +
cauline +  and basal +
divided +  and lanceolate +
opposite +, subopposite +  and alternate +
broadly elliptic +  and obovate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0 (?) +  and 4 (?) +
free +  and distinct +
5 +  and 4 +
Flowering Mar–Jun +  and fruiting Apr–Jul. +
adnate +, free +, connate +  and distinct +
Ann. Sci. Nat., Bot., sér. +
not arillate +
persistent +
free +  and distinct +
ascending +  and spreading +
tuberculose-thickened +
Endemic +  and Illustrated +
nearly +  and glabrous +
subglobose +, cylindric +  and headlike +
free +  and distinct +
ascending +  and erect +
1 +  and 10 +
deciduous +
distinct +
basal +, lateral +, subterminal +  and terminal +
not elongate +
Sanguisorba annua +
Poteridium annuum +
Poteridium +
species +
inconspicuous +
enlarged +  and small +
biennial +  and winter-annual +