FNA: Arctostaphylos osoensis vs. Arctostaphylos rudis

	Arctostaphylos osoensis	Arctostaphylos rudis
	oso manzanita	sand mesa manzanita, shagbark manzanita
Habit	Shrubs, erect or mound-forming, 1–4 m; burl absent; bark of older stems persistent, gray, shredded, sometimes red, smooth; twigs sparsely short-hairy.	Shrubs, erect, 1–3 m; burl present or absent; bark on older stems persistent, gray, shredded; twigs sparsely short-hairy.
Leaves	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.	erect; petiole 3–8 mm; blade bright green, shiny, elliptic, 1–3 × 1–2 cm, base cuneate to rounded, margins entire, plane, surfaces smooth, puberulent, glabrescent.
Inflorescences	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.	racemes, (simple or 1-branched); immature inflorescence pendent, axis 0.5–1 cm, 1+ mm diam., sparsely short-hairy; bracts not appressed, scalelike, deltate, 2–6 mm, apex acuminate, surfaces glabrous.
Pedicels	8–9 mm, glabrous.	3–6 mm, glabrous.
Flowers	corolla white, urceolate; ovary glabrous.	corolla white, conic to urceolate; ovary glabrous.
Fruits	depressed-globose, 5–8 mm diam., glabrous.	depressed-globose, 8–14 mm diam., glabrous.
Stones	distinct.	distinct.
2n	= 26.	= 26.

	Arctostaphylos osoensis	Arctostaphylos rudis
Phenology	Flowering winter–early spring.	Flowering winter–early spring.
Habitat	Maritime chaparral on volcanic uplands	Maritime chaparral on sandy soils
Elevation	0-200 m (0-700 ft)	0-100 m (0-300 ft)
Distribution	CA [BONAP county map]	CA [WildflowerSearch map] [BONAP county map]
Discussion	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.)	Of conservation concern. Arctostaphylos rudis is found along the coast in Nipomo and Burton mesas and Point Sal, Santa Barbara and San Luis Obispo counties. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 8, p. 434.	FNA vol. 8, p. 416.
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. 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	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. 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. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida
Name authority	P. V. Wells: Four Seasons 9(2): 45. 1992 ,	Jepson & Weislander: Erythea 8: 100. 1938 ,
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 osoensis

Arctostaphylos rudis

oso manzanita

sand mesa manzanita, shagbark manzanita

Habit

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

Shrubs, erect, 1–3 m; burl present or absent; bark on older stems persistent, gray, shredded; twigs sparsely short-hairy.

Leaves

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.

erect;

petiole 3–8 mm;

blade bright green, shiny, elliptic, 1–3 × 1–2 cm, base cuneate to rounded, margins entire, plane, surfaces smooth, puberulent, glabrescent.

Inflorescences

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.

racemes, (simple or 1-branched);

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

bracts not appressed, scalelike, deltate, 2–6 mm, apex acuminate, surfaces glabrous.

Pedicels

8–9 mm, glabrous.

3–6 mm, glabrous.

Flowers

corolla white, urceolate;

ovary glabrous.

corolla white, conic to urceolate;

ovary glabrous.

Fruits

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

depressed-globose, 8–14 mm diam., glabrous.

Stones

distinct.

= 26.

Arctostaphylos osoensis

Arctostaphylos rudis

Phenology

Flowering winter–early spring.

Habitat

Maritime chaparral on volcanic uplands

Maritime chaparral on sandy soils

Elevation

0-200 m (0-700 ft)

0-100 m (0-300 ft)

Distribution

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

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.)

Of conservation concern.

Arctostaphylos rudis is found along the coast in Nipomo and Burton mesas and Point Sal, Santa Barbara and San Luis Obispo counties.

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

Source

FNA vol. 8, p. 434.

FNA vol. 8, p. 416.

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. 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

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. 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. sensitiva, A. silvicola, A. stanfordiana, A. tomentosa, A. uva-ursi, A. virgata, A. viridissima, A. viscida

Name authority

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

Jepson & Weislander: Erythea 8: 100. 1938 ,

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

Arctostaphylos osoensis

Arctostaphylos rudis

Arctostaphylos osoensis

Arctostaphylos rudis