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pine nut mountain mousetail, pine nut mountains ivesia

Pickering's ivesia, silky mousetail

Habit Plants grayish green to silvery, sometimes reddish tinged; glands sparse. Plants grayish green; glands abundant.
Stems

prostrate-decumbent to ascending, 0.5–2(–3) dm.

ascending to erect, 3–5 dm.

Basal leaves

6–12(–15) cm; sheathing base weakly strigose abaxially;

stipules absent;

petiole (1–)1.5–2.5(–3) cm, hairs abundant, ascending to spreading, 1–4 mm;

leaflets 15–25 per side, loosely overlapping, (1.5–)2–7 mm, lobes 0–4(–6), lanceolate or oblanceolate to elliptic, hairs abundant, spreading to ascending, 1–3 mm.

8–20 cm; sheathing base ± strigose abaxially;

stipules linear to narrowly lanceolate, 3–5 mm;

petiole 1–3.5 cm, hairs abundant, ascending to spreading, 1–2 mm;

leaflets 35–50 per side, loosely overlapping, 2–6 mm, lobes 3–5, oblanceolate to obovate or oval, hairs abundant, ± ascending, 1–2(–3) mm.

Cauline leaves

2–5.

5–10.

Inflorescences

(7–)15–50-flowered, 2–8 cm diam., flowers arranged individually and/or in several to many loose few-flowered glomerules.

10–100-flowered, (1.5–)5–15 cm diam., flowers usually arranged individually, sometimes more congested.

Pedicels

(3–)6–15(–22) mm.

(1–)2–10 mm.

Flowers

8–13 mm diam.;

epicalyx bractlets lanceolate to elliptic, 2–3 mm;

hypanthium patelliform to shallowly cupulate, 1.5–2.5 × 3–4.5 mm, ± 1/2 as deep as wide;

sepals often purple-suffused, 2.3–4(–5) mm, acute;

petals white, broadly spatulate or obovate to orbiculate, (2.8–)3–5(–6) mm;

stamens 20, filaments filiform, (1–)1.5–3 mm, anthers light pink, 0.3–0.5 mm;

carpels 8–20, styles 2.2–3 mm.

8–13 mm diam.;

epicalyx bractlets linear-lanceolate to lanceolate, (1.8–)2–2.5 mm;

hypanthium cupulate to turbinate, 1.5–3 × 2.5–4 mm, often nearly as deep as wide;

sepals often purple-suffused or -mottled, (2.5–)3–5 mm, acuminate;

petals white, becoming pink-tinged with age, oblanceolate to narrowly spatulate, (2.8–)3–5(–6) mm;

stamens 20, filaments filiform, 1.5–2.3 mm, anthers white to cream, 0.3–0.6 mm;

carpels 2–4, styles 2.5–3.5 mm.

Achenes

light brown, 1.2–1.3 mm.

dark brown, 2.5–3 mm.

Ivesia pityocharis

Ivesia pickeringii

Phenology Flowering summer. Flowering summer.
Habitat Vernally saturated meadows, in sagebrush communities Moist, rocky, grassy meadows, mainly on ultramafic-derived clayey soil, in montane conifer woodlands
Elevation 2100–2700 m (6900–8900 ft) 800–1500 m (2600–4900 ft)
Distribution
from FNA
NV
[BONAP county map]
from FNA
CA
[BONAP county map]
Discussion

Of conservation concern.

Ivesia pityocharis is known only from the Pine Nut Mountains, Douglas County. Plants are somewhat intermediate between those of I. kingii and I. sericoleuca in having relatively shallow hypanthia and loosely sericeous vestiture. Hairs on petioles and stem bases of I. pityocharis are to 4 mm; those of I. kingii are 1 mm and generally appressed-ascending.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Of conservation concern.

Ivesia pickeringii is known from Siskiyou and Trinity counties. Some early treatments (for example, P. A. Rydberg 1898, 1908–1918; W. L. Jepson [1923–1925], 1909–1943, vol. 2) conflated this species with I. aperta, hence reports of I. pickeringii in the Sierra Nevada. Historic collections from Edgewood, at the headwaters of the Shasta River in Siskiyou County, have inflorescences more glomerulate than elsewhere in the species range.

The chromosome count of 2n = 28 (P. A. Munz 1959) needs confirmation. If based on Kruckeberg 3665, which was distributed as a voucher for that count, the determination of this collection has been changed to Ivesia sericoleuca.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 9, p. 241. FNA vol. 9, p. 239.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Unguiculatae Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Unguiculatae
Sibling taxa
I. aperta, I. argyrocoma, I. arizonica, I. baileyi, I. callida, I. campestris, I. cryptocaulis, I. gordonii, I. jaegeri, I. kingii, I. longibracteata, I. lycopodioides, I. muirii, I. multifoliolata, I. paniculata, I. patellifera, I. pickeringii, I. pygmaea, I. rhypara, I. sabulosa, I. santolinoides, I. saxosa, I. sericoleuca, I. setosa, I. shockleyi, I. tweedyi, I. unguiculata, I. utahensis, I. webberi
I. aperta, I. argyrocoma, I. arizonica, I. baileyi, I. callida, I. campestris, I. cryptocaulis, I. gordonii, I. jaegeri, I. kingii, I. longibracteata, I. lycopodioides, I. muirii, I. multifoliolata, I. paniculata, I. patellifera, I. pityocharis, I. pygmaea, I. rhypara, I. sabulosa, I. santolinoides, I. saxosa, I. sericoleuca, I. setosa, I. shockleyi, I. tweedyi, I. unguiculata, I. utahensis, I. webberi
Synonyms Potentilla pickeringii
Name authority Ertter: Syst. Bot. 14: 241, fig. 6. (1989) Torrey ex A. Gray: Proc. Amer. Acad. Arts 6: 531. (1865)
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