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purpusia, rock whitefeather

pine nut mountain mousetail, pine nut mountains ivesia

Habit Plants green, ± tufted, often forming hanging clumps, sometimes rosetted. Plants grayish green to silvery, sometimes reddish tinged; glands sparse.
Stems

pendent or prostrate to ascending, (0.2–)0.5–1.6(–3) dm.

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

Basal leaves

planar, 2–15(–20) cm; sheathing base usually not strigose abaxially;

petiole 3–10 cm;

lateral leaflets (2–)3–4(–5) per side, separate, broadly ovate or obovate to orbiculate, (2–)5–15(–18) mm, incised 1/4–3/4 to base into (3–)7–11 ± ovate teeth, apex not setose, surfaces ± sparsely short-pilose, ± glandular;

terminal leaflets ± distinct.

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.

Cauline leaves

1–3;

blade well developed.

2–5.

Inflorescences

(1–)5–30(–150)-flowered, open, 0.5–14 cm diam.

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

Pedicels

5–30 mm.

(3–)6–15(–22) mm.

Flowers

6–12 mm diam.;

epicalyx bractlets 0(–3), lanceolate, 0.9–1.8 mm;

hypanthium turbinate or campanulate, 1.5–3(–5) × 1–3(–4) mm;

sepals 2–4(–5) mm, acute;

petals yellow or white, oblanceolate to elliptic or obovate, (1.6–)2–4 mm;

stamens 5, filaments 0.8–1.3 mm, anthers ± yellow, oblong to narrowly ovate, 0.6–1.5 mm;

carpels (2–)6–10(–13), atop a stipelike torus, styles 0.9–1.8 mm.

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.

Achenes

greenish white to light tan, 1.2–2 mm, faintly rugose, ± carunculate.

light brown, 1.2–1.3 mm.

Ivesia arizonica

Ivesia pityocharis

Phenology Flowering summer.
Habitat Vernally saturated meadows, in sagebrush communities
Elevation 2100–2700 m (6900–8900 ft)
Distribution
from FNA
AZ; CA; NV; UT
[BONAP county map]
from FNA
NV
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Because the epithet saxosa was retained for Potentilla saxosa upon transfer to Ivesia, a different epithet (arizonica) was needed when Purpusia was likewise transferred in the same publication (B. Ertter 1989). The correct name for this species in Potentilla is P. osterhoutii (A. Nelson) J. T. Howell, due to the existence of P. arizonica.

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

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.)

Key
1. Petals yellow; hypanthia campanulate.
var. arizonica
1. Petals white; hypanthia turbinate.
var. saxosa
Source FNA vol. 9, p. 224. FNA vol. 9, p. 241.
Parent taxa Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Unguiculatae
Sibling taxa
I. aperta, I. argyrocoma, 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. 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
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
Subordinate taxa
I. arizonica var. arizonica, I. arizonica var. saxosa
Synonyms Purpusia arizonica
Name authority (Eastwood ex J. T. Howell) Ertter: Syst. Bot. 14: 233. (1989) Ertter: Syst. Bot. 14: 241, fig. 6. (1989)
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