Rosa watsoniana (Species?)

Garden and Forest, October 1, 1890
Rosa Watsoniana

THIS curious Rose, of which a figure appears on page 477 of this issue, has been grown in the Arnold Arboretum during the last dozen years. It came to the Arboretum from the garden of Mr. Edward S. Rand, in Dedham, Massachusetts, who had obtained it, if I remember rightly, from a garden in Albany, New York. It was supposed to have been brought from Japan and to be a cultivated form of a variety of Rosa multiflora. Its Japanese or Chinese origin is probable, but Monsieur Crépin, whose knowledge of roses is unrivaled and to whom specimens from the Arboretum have been submitted, points out certain characters which separate it from that species and from another east Asia species of the same section (Synstylae), R. anemomeflora, to which, however, it is closely related. The fact that the plants although perfectly hardy and flowering profusely every year produce no seed, would seem to suggest some long cultivated abnormal form from a Japanese garden, a view which is further strengthened by the fact that wild specimens of this plant have not been collected.

*Crépin, Bull. Bot. Soc. Belg., xxvii, part 2, 98; Jour. Royal Hort. Soc., London, xi, part 3, 2. Revue d'Horticulture Belge et Étrangère, xiv, 183, f. 16.

Rosa Walsoniana* is a graceful plant with slender semi-prostrate stems armed with slender recurved spines. The leaves are three or sometimes five-foliolate with pubescent glandular petioles armed with minute recurved spines, and with very narrow, adnate, entire, hairy stipules. The leaflets are narrowly lanceolate or linear, contracted at the two ends and at the apex into a long slender point; they are pubescent on the lower surface along the midrib, entire, with sinuate wavy margins, and are two or two and a half inches long, the broadest less than a quarter of an inch wide. The inflorescence is many-flowered, pyramidal, four or five inches long, three or four inches broad, the primary bracts awl-shaped, hairy, deciduous with the opening of the flowers. The slender pedicels are jointed and provided with minute membranaceous, caducous bracts. The flower-buds are ovoid and slightly hairy. The sepals are narrowly lanceolate entire, subulate-pointed, and covered thickly on the inner surface with dense pubescence. The petals, which are obovate, pointed at the apex, entire, pale rose-colored, form a corolla less than half an inch across when the flower is fully opened. The column of united styles is slender, elongated, and glabrous The flowers open about the middle of June.

Rosa Watsoniana possesses considerable interest as a curiosity among Roses, but little beauty or value as a garden plant from the ordinary horticultural point of view and it will probably never be very much grown, either for its remarkable foliage or its minute flowers. It has proved, however, an admirable stock for several of the Hybrid Perpetual Roses, and has already been propagated to a considerable extent for this purpose in the neighborhood of Boston.

Our illustration is from a specimen grown in the Arboretum.— C. S. S.