FNA: Ivesia argyrocoma vs. Ivesia paniculata

	Ivesia argyrocoma	Ivesia paniculata
	silver-hair ivesia, silverhair mousetail	Ash Creek ivesia, Ash Creek mousetail
Habit		Plants grayish, ± matted.
Stems		± prostrate, 0.4–1.5(–2) dm.
Basal leaves		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; blade reduced.
Inflorescences		20–200-flowered, congested, (1–)1.5–6(–10) cm diam.
Pedicels		1.5–6 mm.
Flowers		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		brown, 0.8–1.5 mm, smooth, prominently carunculate.

	Ivesia argyrocoma	Ivesia paniculata
Phenology		Flowering summer.
Habitat		Dry shallow volcanic ash and cinders atop volcanic bedrock, open sagebrush communities, adjacent conifer woodlands
Elevation		1500–1800 m (4900–5900 ft)
Distribution	CA; nw Mexico [WildflowerSearch map] [BONAP county map]	CA [BONAP county map]
Discussion	Varieties 2 (1 in the flora). Plants from the central Sierra San Pedro Mártir in northern Baja California belong to var. moranii Ertter & Reveal, which may be distinguished by its compact stature (to 0.5 dm), densely villous basal stipules 2–4 mm, decumbent stems 2–7 cm that are stipitate-glandular under the villous indumentum, and solitary, loosely congested cyme. The petals are oblanceolate to narrowly obovate and 2.5–3.5 mm. The grayish, faintly mottled achenes are 1.3–2 mm. (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. 242.	FNA vol. 9, p. 229.
Parent taxa	Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Unguiculatae	Rosaceae > subfam. Rosoideae > tribe Potentilleae > Ivesia > sect. Setosae
Sibling taxa	I. aperta, 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. 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
Subordinate taxa	I. argyrocoma var. argyrocoma
Synonyms	Horkelia argyrocoma, Potentilla argyrocoma
Name authority	(Rydberg) Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 284. (1908)	T. W. Nelson & J. P. Nelson: Brittonia 33: 165, fig. 1. (1981)
Web links	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

silver-hair ivesia, silverhair mousetail

Ash Creek ivesia, Ash Creek mousetail

Habit

Plants grayish, ± matted.

Stems

± prostrate, 0.4–1.5(–2) dm.

Basal leaves

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;

blade reduced.

Inflorescences

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

Pedicels

1.5–6 mm.

Flowers

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

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

Ivesia argyrocoma

Ivesia paniculata

Phenology

Flowering summer.

Habitat

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

Elevation

1500–1800 m (4900–5900 ft)

Distribution

CA; nw Mexico

[WildflowerSearch map]

[BONAP county map]

Discussion

Varieties 2 (1 in the flora).

Plants from the central Sierra San Pedro Mártir in northern Baja California belong to var. moranii Ertter & Reveal, which may be distinguished by its compact stature (to 0.5 dm), densely villous basal stipules 2–4 mm, decumbent stems 2–7 cm that are stipitate-glandular under the villous indumentum, and solitary, loosely congested cyme. The petals are oblanceolate to narrowly obovate and 2.5–3.5 mm. The grayish, faintly mottled achenes are 1.3–2 mm.

(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. 242.

FNA vol. 9, p. 229.

Parent taxa

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

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

Sibling taxa

I. aperta, 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. 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

Subordinate taxa

I. argyrocoma var. argyrocoma

Synonyms

Horkelia argyrocoma, Potentilla argyrocoma

Name authority

(Rydberg) Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 284. (1908)

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

The species comparison tool is brought to you by:

Flora of North America species comparison

Ivesia argyrocoma

Ivesia paniculata

Ivesia argyrocoma

Ivesia paniculata