OregonFlora: Arctostaphylos patula

	Arctostaphylos patula
	green-leaved manzanita
Habit	Shrubs erect, 1–2 m, rarely with an enlarged basal crown (burl) sprouting after fires, often clonal; bark reddish to blackish, smooth, often flaky on branches; lower branches prostrate and rooting, usually finely blackish or yellowish glandular on branchlets.
Leaves	blades broadly lanceolate to ovate or rounded; (2)2.5–6 × 1.5–4 cm, green, bases rounded or truncate; tips acute or obtuse, sometimes rounded; surfaces finely blackish or yellowish glandular hairy near base, becoming glabrous; petioles 6–15(20) mm, with usually minutely glandular hairs.
Inflorescences	panicles, rarely racemes; axis finely glandular, rarely glabrous; long-bracted at bases or not.
Pedicels	2–8 mm, glabrous; bracts at pedicel bases erect, triangular; acute to acuminate, glabrous or minutely glandular.
Flowers	corollas pink; ovaries glabrous.
Fruits	dark brown to brownish red.
2n	=26.

	Arctostaphylos patula
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Shrublands, conifer forests, open slopes, flats on gravelly, sandy, or pumice soils, clear-cuts and other disturbed sites, rarely on serpentine. Flowering Mar–Jun. 100–2400 m. BR, Casc, CR, ECas, Lava, Sisk. CA, NV, WA; northeast to MT, southeast to NM, south to Mexico. Native. This species often has a low, rounded growth form, spreading by rooting of the lower branches, and usually propagating by seeds following clear-cuts or fires. The burl-forming habit often present in A. patula in other states is uncommon in Oregon, found only in some populations in southwestern counties bordering California. No taxonomic distinction is made here between plants with and without burls. Leaf blades with acutely tapering bases are characteristic of related A. hispidula, but may also occur occasionally in A. patula well outside the range of this other species. Hybridization may occur with A. uva-ursi and A. nevadensis. In Curry County, some specimens having canescent puberulence on their inflorescences and floral pedicels and may represent hybrids of A. patula with A. canescens.
Source	Flora of Oregon, volume 2, page 620 Kenton Chambers
Sibling taxa	A. canescens, A. canescens x Arctostaphylos nevadensis, A. canescens x Arctostaphylos patula, A. columbiana, A. columbiana x Arctostaphylos nevadensis, A. glandulosa, A. hispidula, A. mewukka, A. nevadensis, A. nevadensis x Arctostaphylos patula, A. patula x Arctostaphylos uva-ursi, A. patula x Arctostaphylos viscida, A. uva-ursi, A. viscida
Web links	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Arctostaphylos patula

green-leaved manzanita

Habit

Shrubs erect, 1–2 m, rarely with an enlarged basal crown (burl) sprouting after fires, often clonal; bark reddish to blackish, smooth, often flaky on branches; lower branches prostrate and rooting, usually finely blackish or yellowish glandular on branchlets.

Leaves

blades broadly lanceolate to ovate or rounded; (2)2.5–6 × 1.5–4 cm, green, bases rounded or truncate;

tips acute or obtuse, sometimes rounded;

surfaces finely blackish or yellowish glandular hairy near base, becoming glabrous;

petioles 6–15(20) mm, with usually minutely glandular hairs.

Inflorescences

panicles, rarely racemes;

axis finely glandular, rarely glabrous; long-bracted at bases or not.

Pedicels

2–8 mm, glabrous;

bracts at pedicel bases erect, triangular; acute to acuminate, glabrous or minutely glandular.

Flowers

corollas pink;

ovaries glabrous.

Fruits

dark brown to brownish red.

=26.

Arctostaphylos patula

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Shrublands, conifer forests, open slopes, flats on gravelly, sandy, or pumice soils, clear-cuts and other disturbed sites, rarely on serpentine. Flowering Mar–Jun. 100–2400 m. BR, Casc, CR, ECas, Lava, Sisk. CA, NV, WA; northeast to MT, southeast to NM, south to Mexico. Native.

This species often has a low, rounded growth form, spreading by rooting of the lower branches, and usually propagating by seeds following clear-cuts or fires. The burl-forming habit often present in A. patula in other states is uncommon in Oregon, found only in some populations in southwestern counties bordering California. No taxonomic distinction is made here between plants with and without burls. Leaf blades with acutely tapering bases are characteristic of related A. hispidula, but may also occur occasionally in A. patula well outside the range of this other species. Hybridization may occur with A. uva-ursi and A. nevadensis. In Curry County, some specimens having canescent puberulence on their inflorescences and floral pedicels and may represent hybrids of A. patula with A. canescens.