FNA: Arctostaphylos insularis vs. Arctostaphylos auriculata

	Arctostaphylos insularis	Arctostaphylos auriculata
	island manzanita	Mount Diablo manzanita, Mt. Diablo manzanita
Habit	Shrubs, erect, (arborescent), 2–5 m; burl absent; (lower stems reddish with glaucous patches); twigs glabrous, sometimes sparsely short-hairy or sparsely glandular-hairy.	Shrubs, erect, 1–4.5 m; burl absent; twigs densely white-hairy with long, white hairs.
Leaves	bifacial in stomatal distribution; petiole 4–8 mm; blade bright green, lustrous, oblong-elliptic, 2.5–4.5 × 1–3 cm, base rounded, margins entire, ± cupped, surfaces smooth, glabrous.	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.
Inflorescences	panicles, 5–10-branched; immature inflorescence pendent, branches spreading, ascending, or erect, axis 2–3 cm, 1+ mm diam., glabrous, sometimes sparsely short-hairy or sparsely glandular-hairy, (buds ± spread apart); bracts not appressed, scalelike, deltate, 1.5–3 mm, apex acute, surfaces finely glandular-hairy.	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.
Pedicels	6–9 mm, finely glandular-hairy.	4–10 mm, tomentose.
Flowers	corolla white, conic to urceolate; ovary glabrous or sparsely glandular-hairy.	corolla white to pink, conic; ovary densely white-hairy.
Fruits	depressed-globose, 8–15 mm diam., sparsely hairy or glabrous.	depressed-globose, 5–10 mm diam., short white-hairy, glabrescent.
Stones	distinct.	distinct.
2n	= 26.	= 26.

	Arctostaphylos insularis	Arctostaphylos auriculata
Phenology	Flowering winter–early spring.	Flowering winter–early spring.
Habitat	Island chaparral and woodlands	Chaparral, open, closed-cone conifer forests
Elevation	200-400 m (700-1300 ft)	300-500 m (1000-1600 ft)
Distribution	CA [WildflowerSearch map] [BONAP county map]	CA [BONAP county map]
Discussion	Of conservation concern. Arctostaphylos insularis is known from Santa Cruz Island. (Discussion copyrighted by Flora of North America; reprinted with permission.)	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.)
Source	FNA vol. 8, p. 422.	FNA vol. 8, p. 430.
Parent taxa	Ericaceae > subfam. Arbutoideae > Arctostaphylos	Ericaceae > subfam. Arbutoideae > Arctostaphylos
Sibling taxa	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. 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. 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
Synonyms	A. insularis var. pubescens
Name authority	Greene ex Parry: Bull. Calif. Acad. Sci. 2: 494. 1887 ,	Eastwood: Bull. Torrey Bot. Club 32: 202. 1905 ,
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 insularis

Arctostaphylos auriculata

island manzanita

Mount Diablo manzanita, Mt. Diablo manzanita

Habit

Shrubs, erect, (arborescent), 2–5 m; burl absent; (lower stems reddish with glaucous patches); twigs glabrous, sometimes sparsely short-hairy or sparsely glandular-hairy.

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

Leaves

bifacial in stomatal distribution;

petiole 4–8 mm;

blade bright green, lustrous, oblong-elliptic, 2.5–4.5 × 1–3 cm, base rounded, margins entire, ± cupped, surfaces smooth, glabrous.

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.

Inflorescences

panicles, 5–10-branched;

immature inflorescence pendent, branches spreading, ascending, or erect, axis 2–3 cm, 1+ mm diam., glabrous, sometimes sparsely short-hairy or sparsely glandular-hairy, (buds ± spread apart);

bracts not appressed, scalelike, deltate, 1.5–3 mm, apex acute, surfaces finely glandular-hairy.

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.

Pedicels

6–9 mm, finely glandular-hairy.

4–10 mm, tomentose.

Flowers

corolla white, conic to urceolate;

ovary glabrous or sparsely glandular-hairy.

corolla white to pink, conic;

ovary densely white-hairy.

Fruits

depressed-globose, 8–15 mm diam., sparsely hairy or glabrous.

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

Stones

distinct.

= 26.

Arctostaphylos insularis

Arctostaphylos auriculata

Phenology

Flowering winter–early spring.

Habitat

Island chaparral and woodlands

Chaparral, open, closed-cone conifer forests

Elevation

200-400 m (700-1300 ft)

300-500 m (1000-1600 ft)

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Of conservation concern.

Arctostaphylos insularis is known from Santa Cruz Island.

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

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.)

Source

FNA vol. 8, p. 422.

FNA vol. 8, p. 430.

Parent taxa

Ericaceae > subfam. Arbutoideae > Arctostaphylos

Sibling taxa

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. 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. 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

Synonyms

A. insularis var. pubescens

Name authority

Greene ex Parry: Bull. Calif. Acad. Sci. 2: 494. 1887 ,

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

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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Flora of North America species comparison

Arctostaphylos insularis

Arctostaphylos auriculata

Arctostaphylos insularis

Arctostaphylos auriculata