There are six species of wild rose on the current Garden Census. Details of each are given in comparison chart referenced below.
Prickly Rose Stems: It grows erect, to 4 feet high, with branching and per the common name, the older stems are dense with straight prickles. Younger stems have prickles on the stem internodes.
Leaves are alternate, pinnate with 5 or 9 oblong leaflets with coarse teeth. Teeth do not go all the way to the base of the leaflet. Each leaflet has either a very short stalk or no stalk but the terminal leaflet has a longer stalk. The leaf stem has a conspicuous stipule with two outward turned teeth, at the base where the leaf stalk joins the stem. The leaf underside usually has fine whitish hair.
The inflorescence is a single flower or two on last years short side branches.
Flowers are 5-parted, 1 to 2-1/3 inches wide and have short thin pedicels (stalks). The hypanthium is ovoid to oblong. The sepals are long-pointed, and spreading when the flower opens. They persist onto the fruit after the petals drop. The petals are pink to rose colored. In the center of the 5 petals there are numerous stamens with yellow anthers surrounding a short, but wide column of yellow-green pistils rising from 18 to 33 carpels. There are several subspecies of this plant and the subspecies that is considered to be native to Minnesota, (subsp. sayi), has sepals that are somewhat wider than other subspecies and have fine hair and the flower pedicel is without hair.
Seed: Flowers mature to a smooth fleshy orange-red rose hip that contains from 10 to 30 achenes (the true seeds). The flower sepals persist onto the apex of the hip. Wild Rose seeds should be sown outside in the Fall. They will germinate in the 2nd year as they need a cold moist period followed by a warm moist period followed by another cold moist period. If seed has been stored for the proper sequence of periods then it should be scarified before planting. Fall planted fresh seeds should not be scarified. While seed is cheap, bare root plants are usually available from native plant nurseries.
Habitat: The plant grows from a rhizomatous crown, with many fine roots in the top soil and several deep roots; it spreads vegetatively by these horizontal rhizomes. The plant is moderately shade tolerant and prefers open wood, rocky ridges and openings in conifer forests, tolerates many soil types and has good drought tolerance. It is primarily a plant of the boreal forests. There is a lot of variation in the species in particular in the amount of hair, glandularity and fruit shape; also a number of roses that were once classed as separate varieties of this species and several other species have been consolidated into this species.
Names: The genus Rosa, is the Latin for 'rose'. The species name, acicularis, is from the Latin and means needle-like, referring to all the prickles. The author name for the plant classification - 'Lindl.' refers to John Lindley FRS, English (1799-1865) English botanist who authored or co-authored a number of articles and books on plants, some with his own colored engravings; he was particularly interested in roses and orchids, an active member of the Royal Horticultural Society and a University professor. He published A Botanical History of Roses in 1820 which described 76 species.
Comparisons: See this comparison chart of the six species of wild rose in the Garden.
Above: Flowers appear on last years short side branches, and usually as solitary flowers not clusters.
Below: A pink flower typical of Prickly Rose which has numerous stamens with yellow anthers and a central column of greenish-yellow pistils.
Below: The leaf of Prickly Rose has 5 to 9 leaflets with (2nd photo) a conspicuous stipule at the base. Leaf nodes can also have a series of prickles.
Below: The fruit forms as the flower matures. The subspecies sayi has a flower pedicle without hair, somewhat broad greenish sepals with fine hair (1st photo). Those sepals wither and persist on the apex of the forming rose hip (2nd photo). Note also that the flowers and resulting hips are usually solitary.
Below: 1st photo - The underside of the leaf is paler in color with very fine whitish hair. 2nd photo - Flowers and fruit form from a new shoot laterally off the prior years wood. 3rd photo - The lower stems of Prickly rose are dense with prickles.
Notes: Smooth Rose is the only rose that Eloise Butler notes as indigenous to the Garden area. Prickly Rose Was introduced to the Garden in Sept. 1919 by Eloise Butler when she brought in 6 plants from Lutsen MN. It was listed on Martha Crone's 1951 Garden census. In Minnesota Prickly Rose is found in several SE Counties and in most counties in the NE part of the state and then ranging along the Canadian border to North Dakota where it is found in a few Canadian border counties. In North America it ranges in the U.S. from Idaho eastward to the coast but no farther south than the Dakotas, Iowa, Illinois, New York, except it penetrates south along the Rocky Mountains. In Canada it is found in all provinces except in the very far north and Labrador. Five species of wild rose are recognized as being native to Minnesota, R. acicularlis, R. blanda, R. arkansana, R. woodsii and a cross between R. woodsii and R. blanda known as Rosa ×dulcissima Lunell (pro sp.) [blanda × woodsii]
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"