Ivesia sect. Stellariopsis

(Baillon) Ertter & Reveal

Novon 17: 317. 2007.

Endemic
Basionym: Potentilla sect. Stellariopsis Baillon Hist. Pl. 1: 370. 1869
Synonyms: Undefined sect. Stellariopsis (Baillon) Rydberg
Treatment appears in FNA Volume 9. Treatment on page 245. Mentioned on page 221.

Plants tufted, not forming hanging clumps, not aromatic; taproot ± stout, not fusiform or fleshy. Stems (1–) 1.5–4 dm. Basal leaves very tightly cylindric (mousetail-like); stipules present; leaflets tightly overlapping, individually scarcely distinguishable, lobed to base, sometimes entire, densely hairy; terminal leaflets indistinct. Cauline leaves 1–3, not paired; blade relatively well developed. Inflorescences open, flowers arranged individually. Pedicels remaining ± straight. Flowers: hypanthium shallowly campanulate; petals not medially reflexed, white, short-clawed, apex rounded; stamens 15, anthers shorter than wide, dehiscing by subterminal pores to short lateral slits; carpels 1. Achenes vertical, smooth, not carunculate.

Discussion

Species 1.

P. A. Rydberg (1898) recognized Stellariopsis at the generic level primarily on the basis of the obcordate anthers, which apparently open by terminal pores, as well as the single carpel, mousetail-like leaves, diffuse inflorescence, and flowers intermediate between Ivesia and Potentilla. J. Soják (2008) argued that the anther character alone justifies generic status. Examination of a series of flowers shows that porelike dehiscence is largely a result of the extreme shortness of the anthers relative to width, such that longer-than-average anthers approach a more typical dehiscence mode. The single carpel and mousetail-like leaves are consistent within the taxon, although both are found elsewhere in the genus (albeit not in the same species). The relatively large, maroon-tipped stipitate glands of the inflorescence branches, including the pedicel and hypanthium, are otherwise unknown in Ivesia.

Selected References

None.

"dm" is not declared as a valid unit of measurement for this property.

not carunculate +
Barbara Ertter +  and James L. Reveal +
(Baillon) Ertter & Reveal +
compound +  and simple +
opposite +  and alternate +
Potentilla sect. Stellariopsis +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
narrowly oblong +  and filiform planar +
0.5 cm5 mm <br />0.005 m <br /> (20 cm200 mm <br />0.2 m <br />) +
reduced +
elongate +
free +  and distinct +
branched +  and simple +
not +  and aggregated +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
unisexual +  and bisexual +
not +  and aggregated +
deciduous +
obliquely ovoid +  and reniform +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
loose +  and capitate +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
crassinucellate +
opposite +  and alternate +
winter-marcescent +
deciduous +  and persistent +
, +  and distinct +
distinguishable +
oblanceolate +  and oval or obovate +
verticillate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0 (?) +  and 4 (?) +
free +  and distinct +
adnate +, free +, connate +  and distinct +
not arillate +
persistent +
free +  and distinct +
erect +  and spreading +
lanceolate +  and broadly ovate or deltate +
free +  and distinct +
branched +  and simple +
reddish +, grayish +  and green +
pendent +  and erect +
2 +  and 20 +
palmate +  and pinnate +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
Undefined sect. Stellariopsis +
not fusiform +
Ivesia sect. Stellariopsis +
section +
inconspicuous +
stipelike +, elongate +, less flat +  and conic or turbinate +
enlarged +
glabrate +  and sparsely densely glandular-puberulent +