FNA: Ivesia muirii vs. Ivesia paniculata

	Ivesia muirii	Ivesia paniculata
	granite mousetail, Muir's ivesia	Ash Creek ivesia, Ash Creek mousetail
Habit	Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy.	Plants grayish, ± matted.
Stems	usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm.	± prostrate, 0.4–1.5(–2) dm.
Basal leaves	very tightly cylindric (mousetail-like, with individual leaflets scarcely distinguishable), 2–5(–10) cm; sheathing base densely strigose abaxially; petiole 0.2–0.8(–1) cm, hairs 0.5–1.5 mm; leaflets 25–40 per side, 0.4–1 mm, densely sericeous, glands obscured, lobes 2–5, obovate or oval to orbiculate, apex not setose.	tightly cylindric, (1.5–)2–5(–7) cm; sheathing base densely hairy abaxially; petiole 0.5–4 cm; lateral leaflets (5–)8–15 per side, overlapping at least distally, ± flabellate, 0.5–2 mm, incised to base or nearly so into (0–)3–8(–15) elliptic to narrowly obovate lobes, apex not or obscurely setose, surfaces densely hirsute, cryptically glandular; terminal leaflets indistinct.
Cauline leaves	(0–)1–2, paired if 2.	(0–)1; blade reduced.
Inflorescences	10–30-flowered, 1–2(–3.5) cm diam.; glomerules usually 1.	20–200-flowered, congested, (1–)1.5–6(–10) cm diam.
Pedicels	0.3–2(–3.5) mm.	1.5–6 mm.
Flowers	5–6 mm diam.; epicalyx bractlets oblong to obovate, 0.5–1 mm; hypanthium shallowly cupulate, 0.5–1(–1.5) × 1.5–2.5 mm; sepals (1–)1.5–2.5 mm, acute; petals yellow, linear to oblanceolate or narrowly oblong, 1–2 mm; stamens 5, filaments 0.3–0.6 mm, anthers yellow, 0.4–0.6 mm; carpels 1–4, styles 0.7–1.2 mm.	4–6 mm diam.; epicalyx bractlets 5, lanceolate to elliptic, 0.6–1.5(–2) mm; hypanthium shallowly cupulate, 1 × 2–3 mm; sepals (1–)1.5–2.5(–3) mm, acute; petals white to pale yellowish, linear, 1 mm; stamens 5, filaments 0.3–1 mm, anthers yellow with maroon margins, ovate, 0.3–0.5 mm; carpels 1–2(–3), styles 0.7–1.8 mm.
Achenes	grayish brown, mottled with red, 1.6–2 mm.	brown, 0.8–1.5 mm, smooth, prominently carunculate.

	Ivesia muirii	Ivesia paniculata
Phenology	Flowering summer.	Flowering summer.
Habitat	Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra	Dry shallow volcanic ash and cinders atop volcanic bedrock, open sagebrush communities, adjacent conifer woodlands
Elevation	2900–4000 m (9500–13100 ft)	1500–1800 m (4900–5900 ft)
Distribution	CA [WildflowerSearch map] [BONAP county map]	CA [BONAP county map]
Discussion	Ivesia muirii is known from alpine areas in the Sierra Nevada. It is one of the more distinctive species of the genus, in its silvery mousetail-like leaves and usually tightly capitate inflorescences. Putative hybrids are known with I. lycopodioides (D. D. Keck 1938) and I. pygmaea (Center Basin area of Tulare County). (Discussion copyrighted by Flora of North America; reprinted with permission.)	Of conservation concern. Ivesia paniculata is known only from the Ash Valley area of Lassen County. The distinctions between I. paniculata and I. rhypara are perhaps on the same scale as variation among disjunct population clusters of I. rhypara, but no taxonomic adjustments are proposed at this time. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 9, p. 236.	FNA vol. 9, p. 229.
Parent taxa	Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia	Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae
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. 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. 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
Synonyms	Potentilla muirii
Name authority	A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873)	T. W. Nelson & J. P. Nelson: Brittonia 33: 165, fig. 1. (1981)
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Ivesia paniculata

granite mousetail, Muir's ivesia

Ash Creek ivesia, Ash Creek mousetail

Habit

Plants silvery, usually ± rosetted; taproot stout, sometimes fleshy.

Plants grayish, ± matted.

Stems

usually ± erect, sometimes nearly prostrate, 0.5–1.5(–2) dm.

± prostrate, 0.4–1.5(–2) dm.

Basal leaves

very tightly cylindric (mousetail-like, with individual leaflets scarcely distinguishable), 2–5(–10) cm; sheathing base densely strigose abaxially;

petiole 0.2–0.8(–1) cm, hairs 0.5–1.5 mm;

leaflets 25–40 per side, 0.4–1 mm, densely sericeous, glands obscured, lobes 2–5, obovate or oval to orbiculate, apex not setose.

tightly cylindric, (1.5–)2–5(–7) cm; sheathing base densely hairy abaxially;

petiole 0.5–4 cm;

lateral leaflets (5–)8–15 per side, overlapping at least distally, ± flabellate, 0.5–2 mm, incised to base or nearly so into (0–)3–8(–15) elliptic to narrowly obovate lobes, apex not or obscurely setose, surfaces densely hirsute, cryptically glandular;

terminal leaflets indistinct.

Cauline leaves

(0–)1–2, paired if 2.

(0–)1;

blade reduced.

Inflorescences

10–30-flowered, 1–2(–3.5) cm diam.;

glomerules usually 1.

20–200-flowered, congested, (1–)1.5–6(–10) cm diam.

Pedicels

0.3–2(–3.5) mm.

1.5–6 mm.

Flowers

5–6 mm diam.;

epicalyx bractlets oblong to obovate, 0.5–1 mm;

hypanthium shallowly cupulate, 0.5–1(–1.5) × 1.5–2.5 mm;

sepals (1–)1.5–2.5 mm, acute;

petals yellow, linear to oblanceolate or narrowly oblong, 1–2 mm;

stamens 5, filaments 0.3–0.6 mm, anthers yellow, 0.4–0.6 mm;

carpels 1–4, styles 0.7–1.2 mm.

4–6 mm diam.;

epicalyx bractlets 5, lanceolate to elliptic, 0.6–1.5(–2) mm;

hypanthium shallowly cupulate, 1 × 2–3 mm;

sepals (1–)1.5–2.5(–3) mm, acute;

petals white to pale yellowish, linear, 1 mm;

stamens 5, filaments 0.3–1 mm, anthers yellow with maroon margins, ovate, 0.3–0.5 mm;

carpels 1–2(–3), styles 0.7–1.8 mm.

Achenes

grayish brown, mottled with red, 1.6–2 mm.

brown, 0.8–1.5 mm, smooth, prominently carunculate.

Ivesia muirii

Ivesia paniculata

Phenology

Flowering summer.

Habitat

Dry rocky slopes, fellfields, mostly in alpine conifer woodlands and tundra

Dry shallow volcanic ash and cinders atop volcanic bedrock, open sagebrush communities, adjacent conifer woodlands

Elevation

2900–4000 m (9500–13100 ft)

1500–1800 m (4900–5900 ft)

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Ivesia muirii is known from alpine areas in the Sierra Nevada. It is one of the more distinctive species of the genus, in its silvery mousetail-like leaves and usually tightly capitate inflorescences. Putative hybrids are known with I. lycopodioides (D. D. Keck 1938) and I. pygmaea (Center Basin area of Tulare County).

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

Of conservation concern.

Ivesia paniculata is known only from the Ash Valley area of Lassen County. The distinctions between I. paniculata and I. rhypara are perhaps on the same scale as variation among disjunct population clusters of I. rhypara, but no taxonomic adjustments are proposed at this time.

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

Source

FNA vol. 9, p. 236.

FNA vol. 9, p. 229.

Parent taxa

Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Ivesia

Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae

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. 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. 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

Synonyms

Potentilla muirii

Name authority

A. Gray: Proc. Amer. Acad. Arts 8: 627. (1873)

T. W. Nelson & J. P. Nelson: Brittonia 33: 165, fig. 1. (1981)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

Choose a data source: Flora of North America

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Ivesia muirii

Ivesia paniculata

Ivesia muirii

Ivesia paniculata