FNA: Arctostaphylos auriculata vs. Arctostaphylos osoensis

	Arctostaphylos auriculata	Arctostaphylos osoensis
	Mount Diablo manzanita, Mt. Diablo manzanita	oso manzanita
Habit	Shrubs, erect, 1–4.5 m; burl absent; twigs densely white-hairy with long, white hairs.	Shrubs, erect or mound-forming, 1–4 m; burl absent; bark of older stems persistent, gray, shredded, sometimes red, smooth; twigs sparsely short-hairy.
Leaves	petiole to 2 mm; blade whitish gray, dull, oblong-ovate to orbiculate-ovate, 1.5–4.5 × 1.5–3 cm, base distinctly lobed, auriculate-clasping, margins entire, plane, surfaces smooth, gray-canescent, glabrescent.	petiole to 2 mm; blade dark green, ± shiny, ovate to orbiculate-ovate, 1.5–3 × 1.5–2.5 cm, base deeply lobed, (clasping), margins entire, plane, surfaces smooth, sparsely short-hairy or glabrous.
Inflorescences	panicles, 3–5-branched; immature inflorescence pendent, (branches crowded, ± obscured by bracts), axis 1–1.5 cm, 1+ mm diam., densely white-hairy with long, white hairs; bracts somewhat appressed, leaflike, ovate to lanceolate-ovate, 5–15 mm, apex acute, surfaces canescent.	racemes, simple or 1-branched; immature inflorescence pendent, (branches compact, framed by bracts), axis 0.5–1 cm, 1+ mm diam., sparsely short-hairy; bracts not appressed, leaflike, lanceolate to ovate, 4–8 mm, apex acute, surfaces glabrous.
Pedicels	4–10 mm, tomentose.	8–9 mm, glabrous.
Flowers	corolla white to pink, conic; ovary densely white-hairy.	corolla white, urceolate; ovary glabrous.
Fruits	depressed-globose, 5–10 mm diam., short white-hairy, glabrescent.	depressed-globose, 5–8 mm diam., glabrous.
Stones	distinct.	distinct.
2n	= 26.	= 26.

	Arctostaphylos auriculata	Arctostaphylos osoensis
Phenology	Flowering winter–early spring.	Flowering winter–early spring.
Habitat	Chaparral, open, closed-cone conifer forests	Maritime chaparral on volcanic uplands
Elevation	300-500 m (1000-1600 ft)	0-200 m (0-700 ft)
Distribution	CA [BONAP county map]	CA [BONAP county map]
Discussion	Of conservation concern. Arctostaphylos auriculata is found on the western slopes of Mount Diablo in Contra Costa County. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Of conservation concern. Arctostaphylos osoensis is found in the volcanic hills east of Morro Bay, San Luis Obispo County. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 8, p. 430.	FNA vol. 8, p. 434.
Parent taxa	Ericaceae > subfam. Arbutoideae > Arctostaphylos	Ericaceae > subfam. Arbutoideae > Arctostaphylos
Sibling taxa	A. andersonii, A. bakeri, A. canescens, A. catalinae, A. columbiana, A. confertiflora, A. crustacea, A. cruzensis, A. densiflora, A. edmundsii, A. franciscana, A. gabilanensis, A. glandulosa, A. glauca, A. glutinosa, A. hispidula, A. hookeri, A. hooveri, A. imbricata, A. insularis, A. klamathensis, A. luciana, A. malloryi, A. manzanita, A. mewukka, A. montana, A. montaraensis, A. montereyensis, A. morroensis, A. myrtifolia, A. nevadensis, A. nissenana, A. nortensis, A. nummularia, A. obispoensis, A. ohloneana, A. osoensis, A. otayensis, A. pacifica, A. pajaroensis, A. pallida, A. parryana, A. patula, A. pechoensis, A. pilosula, A. pringlei, A. pumila, A. pungens, A. purissima, A. rainbowensis, A. refugioensis, A. regismontana, A. rudis, A. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida	A. andersonii, A. auriculata, A. bakeri, A. canescens, A. catalinae, A. columbiana, A. confertiflora, A. crustacea, A. cruzensis, A. densiflora, A. edmundsii, A. franciscana, A. gabilanensis, A. glandulosa, A. glauca, A. glutinosa, A. hispidula, A. hookeri, A. hooveri, A. imbricata, A. insularis, A. klamathensis, A. luciana, A. malloryi, A. manzanita, A. mewukka, A. montana, A. montaraensis, A. montereyensis, A. morroensis, A. myrtifolia, A. nevadensis, A. nissenana, A. nortensis, A. nummularia, A. obispoensis, A. ohloneana, A. otayensis, A. pacifica, A. pajaroensis, A. pallida, A. parryana, A. patula, A. pechoensis, A. pilosula, A. pringlei, A. pumila, A. pungens, A. purissima, A. rainbowensis, A. refugioensis, A. regismontana, A. rudis, A. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida
Name authority	Eastwood: Bull. Torrey Bot. Club 32: 202. 1905 ,	P. V. Wells: Four Seasons 9(2): 45. 1992 ,
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

Arctostaphylos auriculata

Arctostaphylos osoensis

Mount Diablo manzanita, Mt. Diablo manzanita

oso manzanita

Habit

Shrubs, erect, 1–4.5 m; burl absent; twigs densely white-hairy with long, white hairs.

Shrubs, erect or mound-forming, 1–4 m; burl absent; bark of older stems persistent, gray, shredded, sometimes red, smooth; twigs sparsely short-hairy.

Leaves

petiole to 2 mm;

blade whitish gray, dull, oblong-ovate to orbiculate-ovate, 1.5–4.5 × 1.5–3 cm, base distinctly lobed, auriculate-clasping, margins entire, plane, surfaces smooth, gray-canescent, glabrescent.

petiole to 2 mm;

blade dark green, ± shiny, ovate to orbiculate-ovate, 1.5–3 × 1.5–2.5 cm, base deeply lobed, (clasping), margins entire, plane, surfaces smooth, sparsely short-hairy or glabrous.

Inflorescences

panicles, 3–5-branched;

immature inflorescence pendent, (branches crowded, ± obscured by bracts), axis 1–1.5 cm, 1+ mm diam., densely white-hairy with long, white hairs;

bracts somewhat appressed, leaflike, ovate to lanceolate-ovate, 5–15 mm, apex acute, surfaces canescent.

racemes, simple or 1-branched;

immature inflorescence pendent, (branches compact, framed by bracts), axis 0.5–1 cm, 1+ mm diam., sparsely short-hairy;

bracts not appressed, leaflike, lanceolate to ovate, 4–8 mm, apex acute, surfaces glabrous.

Pedicels

4–10 mm, tomentose.

8–9 mm, glabrous.

Flowers

corolla white to pink, conic;

ovary densely white-hairy.

corolla white, urceolate;

ovary glabrous.

Fruits

depressed-globose, 5–10 mm diam., short white-hairy, glabrescent.

depressed-globose, 5–8 mm diam., glabrous.

Stones

distinct.

= 26.

Arctostaphylos auriculata

Arctostaphylos osoensis

Phenology

Flowering winter–early spring.

Habitat

Chaparral, open, closed-cone conifer forests

Maritime chaparral on volcanic uplands

Elevation

300-500 m (1000-1600 ft)

0-200 m (0-700 ft)

Distribution

[BONAP county map]

Discussion

Of conservation concern.

Arctostaphylos auriculata is found on the western slopes of Mount Diablo in Contra Costa County.

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

Of conservation concern.

Arctostaphylos osoensis is found in the volcanic hills east of Morro Bay, San Luis Obispo County.

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

Source

FNA vol. 8, p. 430.

FNA vol. 8, p. 434.

Parent taxa

Ericaceae > subfam. Arbutoideae > Arctostaphylos

Sibling taxa

A. andersonii, A. bakeri, A. canescens, A. catalinae, A. columbiana, A. confertiflora, A. crustacea, A. cruzensis, A. densiflora, A. edmundsii, A. franciscana, A. gabilanensis, A. glandulosa, A. glauca, A. glutinosa, A. hispidula, A. hookeri, A. hooveri, A. imbricata, A. insularis, A. klamathensis, A. luciana, A. malloryi, A. manzanita, A. mewukka, A. montana, A. montaraensis, A. montereyensis, A. morroensis, A. myrtifolia, A. nevadensis, A. nissenana, A. nortensis, A. nummularia, A. obispoensis, A. ohloneana, A. osoensis, A. otayensis, A. pacifica, A. pajaroensis, A. pallida, A. parryana, A. patula, A. pechoensis, A. pilosula, A. pringlei, A. pumila, A. pungens, A. purissima, A. rainbowensis, A. refugioensis, A. regismontana, A. rudis, A. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida

A. andersonii, A. auriculata, A. bakeri, A. canescens, A. catalinae, A. columbiana, A. confertiflora, A. crustacea, A. cruzensis, A. densiflora, A. edmundsii, A. franciscana, A. gabilanensis, A. glandulosa, A. glauca, A. glutinosa, A. hispidula, A. hookeri, A. hooveri, A. imbricata, A. insularis, A. klamathensis, A. luciana, A. malloryi, A. manzanita, A. mewukka, A. montana, A. montaraensis, A. montereyensis, A. morroensis, A. myrtifolia, A. nevadensis, A. nissenana, A. nortensis, A. nummularia, A. obispoensis, A. ohloneana, A. otayensis, A. pacifica, A. pajaroensis, A. pallida, A. parryana, A. patula, A. pechoensis, A. pilosula, A. pringlei, A. pumila, A. pungens, A. purissima, A. rainbowensis, A. refugioensis, A. regismontana, A. rudis, A. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida

Name authority

Eastwood: Bull. Torrey Bot. Club 32: 202. 1905 ,

P. V. Wells: Four Seasons 9(2): 45. 1992 ,

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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Arctostaphylos auriculata

Arctostaphylos osoensis

Arctostaphylos auriculata

Arctostaphylos osoensis