Native California Roses

copyright Barbara Ertter, 2001 back to main rose page


Rosa minutifoliaEngelm.
"Ensenada Rose"

Description Distribution Discussion Horticultural Notes Nomenclature Cited Literature Links

plants forming extensive thickets small deeply cut leaves prominent prickles, prickly-hispid hip


DESCRIPTION: Dense shrub, 3--15 dm tall. Stem gray; prickles many, slender, straight. Leaf 1--2 cm long; stipule margins glandular; leaflets 1--3 per side, hairy; terminal leaflet 3--7 mm long, obovate, the base obtuse, the tip obtuse; leaf-margins toothed ca halfway to midvein, glandless. Inflorescence generally of solitary flowers; pedicels 2--10 mm long, hairy, glandless. Flowers: body of hip in flower 3 mm wide, densely prickly-hispid, neck of hip 2 mm wide; sepals glandless, margins with toothed lateral lobes, sepal-tip generally equalling sepal-body, toothed; petals 10--20 mm long, generally pink, rarely white (forma albiflora W.H. Lewis); pistils generally 10 in number. Hip 5 mm wide, ovoid, densely prickly-hispid, neck 3 mm wide, sepals persistent. n=7.
Blooming February to May. Chaparral; 160 m in California, from sea level to 480 m in Baja California.

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DISTRIBUTION OF ROSA MINUTIFOLIA:
West coast of Baja California Norte, Mexico, and on the Otay Mesa in San Diego Co., California, USA. The species is a common constituent of the coastal scrub community in northern Baja California, extending from near Ensenada to somewhere south of El Rosaria, and inland to the south end of the Sierra San Miguel in central Baja California. The disjunct population from San Diego County, the only one known in the United States, is of conservation concern.

Additional distributional representations available from links at entry for this species in the Jepson Interchange for On-Line Floristics

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DISCUSSION: In contrast to the identification challenge posed by other native roses, Rosa minutifolia is dramatically distinct. Rydberg (1918) placed it in a separate tribe, Minutifoliae, otherwise containing only Rosa stellata Wooton (including R. mirifica Greene) of Arizona, New Mexico, and west Texas. The tiny leaflets (only about 1/4 in. long) of Rosa minutifolia are deeply incised, and the hips are densely prickly. The entire plant, which forms an impenetrable thicket, is so densely prickly that one of the discovers proposed horrida as an appropriate specific epithet.

The history of Discovery of Rosa minutifolia is a story in its own right, called by Lenz (1982) the Thorny Rose Affair.

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HORTICULTURAL NOTES: According to Lenz (1982), five rooted cuttings planted at the Rancho Santa Ana Botanic Garden in 1954 had become "one large tangled mass" nearly 30 feet across by 1982, though the species is otherwise "an extremely rare plant" in horticultural circles. Although generally requiring a hot, dry climate (Krüssmann, 1981), plants are capable of surviving at least as far north as San Francisco (i.e., in the UC Botanical Garden).

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NOMENCLATURE: In The Jepson Manual, the vernacular name of "small-leaved rose" is provided as the English equivalent of Rosa minutifolia. I suggest Ensenada rose as a more euphonious alternative, referring to the largest town in that part of northern Baja California where the species is a common constituent of the coastal scrub community.

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CITED LITERATURE:
Krüssmann, Gerd. 1981. The complete book of roses. Timber Press, Portland, OR. 436 pages. [translation by G. Krüssman & N. Raban of Krüssman, G., 1974, Rosen, Rosen, Rosen]

Lenz, Lee W. 1982. The thorny rose affair: discovery and naming of Rosa minutifolia. Aliso 10:187--217.

Rydberg, Per Axel. 1918. Rosa. North American Flora 22(6): 483--533.

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LINKS:

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