OregonFlora: Arctostaphylos morroensis vs. Arctostaphylos

	Arctostaphylos morroensis	Arctostaphylos
		manzanita
Stems		prostrate to erect, often contorted; much branched, rarely with a much enlarged root-crown (burl); bark shiny brown to dark red or blackish; smooth, often flaky on branches.
Leaves		alternate; simple, elliptic to lanceolate; ovate, or rounded; abaxial and adaxial surfaces similar; dull green or grayish, or adaxial surface brighter green, bases tapered to rounded or truncate; margins entire; tips acute, obtuse, or rounded; petioles short; stipules absent.
Inflorescences		terminal; racemes or panicles, condensed or open; few- to many-flowered, bracteate throughout.
Flowers		bisexual, regular, pedicelled, overwintering in bud; sepals (4)5, connate at base; corollas (4)5-merous; urn-shaped; < 11 mm wide, white or pink; petals connate nearly their entire length, with short distinct, spreading or recurved lobes; stamens (8)10, included in corolla; free; filaments broadened and usually hairy at base; anthers with curved awns, opening by terminal pores; ovaries superior, glabrous or pubescent; compound, 2–10 chambered; styles 1; stigmas capitate, hypogynous disk present.
Fruits		berry- or drupe-like, with 2–10 1-seeded nutlets, brown or red; fleshy, mealy, not warty.
Small trees		or
Shrubs		evergreen.

	Arctostaphylos morroensis	Arctostaphylos
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion		Western North America (1 species circumpolar). ~60 species; 8 species treated in Flora. This genus attains by far its greatest diversity in California, where 85 species and subspecies were recognized (Wells 1993) with even more added in recent years. This extreme proliferation of taxa is generally ascribed to interspecific hybridization followed by the stabilization of recombinant genetic types, often as small, morphologically distinct populations in unique habitats or isolated locations apart from the parental taxa. Our treatment follows a conservative approach, with several earlier recognized Oregon species being placed in synonymy or under various putative interspecific hybrid combinations. Included are two named hybrids of known parentage that, in our opinion, do not have distinct species status. Species identifications are well defined except in the Siskiyou Mountains region of southwestern Oregon, where co-occurring taxa frequently hybridize, especially in disturbed habitats, and key characteristics may recombine. Foliage pubescence traits are often best seen in young leaves, if available.
Source		Flora of Oregon, volume 2, page 617 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, A. patula x Arctostaphylos uva-ursi, A. patula x Arctostaphylos viscida, A. uva-ursi, A. viscida
Subordinate taxa		A. canescens, A. columbiana, A. glandulosa, A. hispidula, A. mewukka, A. nevadensis, A. patula, A. uva-ursi, A. viscida
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria 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, 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 morroensis

Arctostaphylos

manzanita

Stems

prostrate to erect, often contorted; much branched, rarely with a much enlarged root-crown (burl);

bark shiny brown to dark red or blackish; smooth, often flaky on branches.

Leaves

alternate; simple, elliptic to lanceolate; ovate, or rounded; abaxial and adaxial surfaces similar; dull green or grayish, or adaxial surface brighter green, bases tapered to rounded or truncate;

margins entire;

tips acute, obtuse, or rounded;

petioles short;

stipules absent.

Inflorescences

terminal; racemes or panicles, condensed or open; few- to many-flowered, bracteate throughout.

Flowers

bisexual, regular, pedicelled, overwintering in bud;

sepals (4)5, connate at base;

corollas (4)5-merous; urn-shaped; < 11 mm wide, white or pink;

petals connate nearly their entire length, with short distinct, spreading or recurved lobes;

stamens (8)10, included in corolla; free;

filaments broadened and usually hairy at base;

anthers with curved awns, opening by terminal pores;

ovaries superior, glabrous or pubescent; compound, 2–10 chambered;

styles 1;

stigmas capitate, hypogynous disk present.

Fruits

berry- or drupe-like, with 2–10 1-seeded nutlets, brown or red; fleshy, mealy, not warty.

Small trees

Shrubs

evergreen.

Arctostaphylos morroensis

Arctostaphylos

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Western North America (1 species circumpolar). ~60 species; 8 species treated in Flora.

This genus attains by far its greatest diversity in California, where 85 species and subspecies were recognized (Wells 1993) with even more added in recent years. This extreme proliferation of taxa is generally ascribed to interspecific hybridization followed by the stabilization of recombinant genetic types, often as small, morphologically distinct populations in unique habitats or isolated locations apart from the parental taxa. Our treatment follows a conservative approach, with several earlier recognized Oregon species being placed in synonymy or under various putative interspecific hybrid combinations. Included are two named hybrids of known parentage that, in our opinion, do not have distinct species status. Species identifications are well defined except in the Siskiyou Mountains region of southwestern Oregon, where co-occurring taxa frequently hybridize, especially in disturbed habitats, and key characteristics may recombine. Foliage pubescence traits are often best seen in young leaves, if available.

Source

Flora of Oregon, volume 2, page 617
Kenton Chambers

Sibling taxa