FNA: Arctostaphylos imbricata vs. Arctostaphylos pacifica

	Arctostaphylos imbricata	Arctostaphylos pacifica
	San Bruno Mountain manzanita	Pacific manzanita
Habit	Shrubs, prostrate or mat- or mound-forming, 0.1–1 m; burl absent; twigs densely fine-hairy with long, gland-tipped hairs.	Shrubs, prostrate or mound-forming, 0.1–0.3 m; burl present, sometimes epicormic; twigs short-hairy.
Leaves	petiole to 2 mm; blade light green, dull, orbiculate to orbiculate-ovate, 2.5–4 × 2–3 cm, base auriculate-clasping, margins entire, plane, surfaces papillate, ± scabrous, sparsely glandular-hairy.	petiole 2–4 mm; blade light green abaxially, dark green adaxially, shiny, elliptic, 1–2 × 0.5–1 cm, base cuneate, margins serrulate, plane, surfaces smooth, sparsely hairy.
Inflorescences	panicles, 3–5-branched; immature inflorescence pendent, (branches densely clustered, ± sessile), axis 0.5–1 cm, 1+ mm diam., densely fine-hairy with long, gland-tipped hairs; bracts appressed, leaflike, ovate, 5–10 mm, apex acute, surfaces glandular-hairy.	racemes, (simple or 1-branched); immature inflorescence pendent, (congested), axis 0.5–1 cm, 1+ mm diam., short-hairy; bracts appressed, scalelike, awl-like, 0.5–1 mm, apex acute, glabrous.
Pedicels	3–5 mm, densely glandular-hairy.	3–5 mm, glabrous.
Flowers	corolla white, urceolate; ovary densely glandular-hairy.	corolla white, urceolate; ovary glabrous.
Fruits	depressed-globose, 6–7 mm diam., glandular-hairy, (± viscid).	(reddish), globose, 6–8 mm diam., glabrous.
Stones	distinct.	distinct.
2n	= 26.

	Arctostaphylos imbricata	Arctostaphylos pacifica
Phenology	Flowering winter–early spring.	Flowering winter–early spring.
Habitat	Maritime chaparral on sandstone outcroppings	Sandstone outcrops
Elevation	100-200 m (300-700 ft)	300 m (1000 ft)
Distribution	CA [WildflowerSearch map] [BONAP county map]	CA [WildflowerSearch map] [BONAP county map]
Discussion	Of conservation concern. Arctostaphylos imbricata occurs on San Bruno Mountain in San Mateo County. It is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.)	Of conservation concern. A distinctive species with an uncertain origin, Arctostaphylos pacifica has often been relegated to hybrid status and ignored; it displays a number of unique characters not found in any other species. It is found only at one location, San Bruno Mountain, the northern part of the Santa Cruz Mountains, San Mateo County. The relationships of this species need additional study. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 8, p. 435.	FNA vol. 8, p. 415.
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. 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. osoensis, A. otayensis, 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. andersonii var. imbricata
Name authority	Eastwood: Proc. Calif. Acad. Sci., ser. 4, 20: 149. 1931 ,	Roof: Leafl. W. Bot. 9: 217. 1962 ,
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 pacifica

San Bruno Mountain manzanita

Pacific manzanita

Habit

Shrubs, prostrate or mat- or mound-forming, 0.1–1 m; burl absent; twigs densely fine-hairy with long, gland-tipped hairs.

Shrubs, prostrate or mound-forming, 0.1–0.3 m; burl present, sometimes epicormic; twigs short-hairy.

Leaves

petiole to 2 mm;

blade light green, dull, orbiculate to orbiculate-ovate, 2.5–4 × 2–3 cm, base auriculate-clasping, margins entire, plane, surfaces papillate, ± scabrous, sparsely glandular-hairy.

petiole 2–4 mm;

blade light green abaxially, dark green adaxially, shiny, elliptic, 1–2 × 0.5–1 cm, base cuneate, margins serrulate, plane, surfaces smooth, sparsely hairy.

Inflorescences

panicles, 3–5-branched;

immature inflorescence pendent, (branches densely clustered, ± sessile), axis 0.5–1 cm, 1+ mm diam., densely fine-hairy with long, gland-tipped hairs;

bracts appressed, leaflike, ovate, 5–10 mm, apex acute, surfaces glandular-hairy.

racemes, (simple or 1-branched);

immature inflorescence pendent, (congested), axis 0.5–1 cm, 1+ mm diam., short-hairy;

bracts appressed, scalelike, awl-like, 0.5–1 mm, apex acute, glabrous.

Pedicels

3–5 mm, densely glandular-hairy.

3–5 mm, glabrous.

Flowers

corolla white, urceolate;

ovary densely glandular-hairy.

corolla white, urceolate;

ovary glabrous.

Fruits

depressed-globose, 6–7 mm diam., glandular-hairy, (± viscid).

(reddish), globose, 6–8 mm diam., glabrous.

Stones

distinct.

= 26.

Arctostaphylos pacifica

Phenology

Flowering winter–early spring.

Habitat

Maritime chaparral on sandstone outcroppings

Sandstone outcrops

Elevation

100-200 m (300-700 ft)

300 m (1000 ft)

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Of conservation concern.

Arctostaphylos imbricata occurs on San Bruno Mountain in San Mateo County. It is in the Center for Plant Conservation’s National Collection of Endangered Plants.

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

Of conservation concern.

A distinctive species with an uncertain origin, Arctostaphylos pacifica has often been relegated to hybrid status and ignored; it displays a number of unique characters not found in any other species. It is found only at one location, San Bruno Mountain, the northern part of the Santa Cruz Mountains, San Mateo County. The relationships of this species need additional study.

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

Source

FNA vol. 8, p. 435.

FNA vol. 8, p. 415.

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. 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. osoensis, A. otayensis, 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. andersonii var. imbricata

Name authority

Eastwood: Proc. Calif. Acad. Sci., ser. 4, 20: 149. 1931 ,

Roof: Leafl. W. Bot. 9: 217. 1962 ,

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 imbricata

Arctostaphylos pacifica

Arctostaphylos imbricata

Arctostaphylos pacifica