Ivesia aperta

(J. T. Howell) Munz

Suppl. Calif. Fl., 111. 1968.

Conservation concernEndemic
Basionym: Potentilla aperta J. T. Howell Leafl. W. Bot. 9: 239. 1962
Treatment appears in FNA Volume 9. Treatment on page 240. Mentioned on page 238, 239.

Plants greenish gray to silvery; glands sparse. Stems decumbent to erect, 1.5–4.5 dm. Basal leaves (7–) 10–20 (–23) cm; sheathing base densely strigose abaxially; stipules absent; petiole 4–8 cm, hairs abundant, ascending, ± 1 (–3) mm; leaflets 20–35 per side, loosely overlapping, 3–15 (–20) mm, lobes 0–4 (–5), oblanceolate to elliptic, hairs abundant, ascending to appressed, ± 1 (–2) mm. Cauline leaves 3–8. Inflorescences (10–) 20–250-flowered, 1–14 cm diam., flowers arranged in several to many tight glomerules of 5–20 flowers. Pedicels 1–3 (–15) mm. Flowers 5–12 mm diam.; epicalyx bractlets lanceolate, 1.5–2.5 (–3.5) mm; hypanthium cupulate, 1–2 × 2.5–4 (–5) mm, 1/2–2/3 as deep as wide; sepals green, 2.5–4 (–5.5) mm, acute to acuminate; petals light yellow, oblanceolate to broadly obovate, 2–7 mm; stamens 20, filaments filiform, 1–4 mm, anthers yellow, 0.4–0.6 mm; carpels 2–7, styles 2–4 mm. Achenes brown, 2–3 mm.

Discussion

Varieties 2 (2 in the flora).

Many historic collections of Ivesia aperta were identified as I. pickeringii. D. D. Keck (1938) considered I. aperta to be no more than a yellow-flowered form of I. sericoleuca, a situation clarified and rectified by J. T. Howell (1962). The ranges of the two species overlap in Sierra Valley, California, with mixed populations occurring near Beckwourth and in the valleys north of Sierra Valley. In general, var. aperta occurs in the southeastern portions of the valley and I. sericoleuca occurs on the western side; the species are not otherwise sympatric. In addition to petal color, which fades in herbarium material, I. aperta differs from I. sericoleuca in having smaller flowers with shallower hypanthia. Hairs at the base of the stems and petioles of I. aperta are relatively short (to 2 mm) and generally ascending; those of I. sericoleuca are longer (to 4 mm) and spreading. Variety canina combines the petal color of var. aperta and floral dimensions of I. sericoleuca.

Selected References

None.

Key

1 Petals 2–3 mm, oblanceolate; filaments 1–1.5(–2) mm; Sierra Valley drainage, California, Carson and Virginia ranges, Nevada. Ivesia aperta var. aperta
1 Petals usually 4–7 mm, narrowly to broadly obovate; filaments 2–4 mm; Dog Valley, California, Nevada. Ivesia aperta var. canina

No values specified."dm" is not declared as a valid unit of measurement for this property.

... more about "Ivesia aperta"
not carunculate +
less as-long-as to longer than wide +  and more +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
Barbara Ertter +  and James L. Reveal +
(J. T. Howell) Munz +
compound +  and simple +
opposite +  and alternate +
20 cm200 mm <br />0.2 m <br /> (23 cm230 mm <br />0.23 m <br />) +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
Potentilla aperta +
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 +
Calif. +  and Nev. +
not +  and aggregated +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
5 +  and 20 +
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 +
several +  and many +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
ascending +  and appressed +
1 cm10 mm <br />0.01 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1/2 +  and 2/3 +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
(10-)20-250-flowered +
1 cm10 mm <br />0.01 m <br /> (14 cm140 mm <br />0.14 m <br />) +
crassinucellate +
opposite +  and alternate +
winter-marcescent +
deciduous +  and persistent +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
, +  and distinct +
not +  and distinguishable +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
oblanceolate +  and elliptic +
verticillate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
clustered +, biseriate +  and superposed +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 (?) +  and 4 (?) +
free +  and distinct +
0.2 cm2 mm <br />0.002 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
4 cm40 mm <br />0.04 m <br /> (8 cm80 mm <br />0.08 m <br />) +
adnate +, free +, connate +  and distinct +
Suppl. Calif. Fl., +
not arillate +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
persistent +
free +  and distinct +
erect +  and spreading +
acute +  and acuminate +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Conservation concern +  and Endemic +
free +  and distinct +
branched +  and simple +
reddish +, grayish +  and green +
decumbent +  and erect +
2 +  and 20 +
palmate +  and pinnate +
deciduous +
distinct +
subterminal +
filiform +
rough-thickened +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Eremicae +, Ivesia sect. Eremicae +  and Unguiculatae +
Ivesia aperta +
Ivesia sect. Unguiculatae +
species +
glabrate +  and hairy +
inconspicuous +
stipelike +, elongate +, less flat +  and conic or turbinate +
enlarged +
tufted +  and rosetted +
greenish gray +  and silvery +
glabrate +  and sparsely densely glandular-puberulent +