Rosa stellata (Species)

Explanation of Plate 335
Rosa stellata Wooton

FIG. 1. Branch showing bud and flower, natural size. Organ Mountains.

FIG. 2. Young growing branch, natural size. Organ Mountains.

FIG. 3. Single leaf, natural size. Organ Mountains.

FIG. 4. Section of flower, natural size. Organ Mountains.

FIG. 5. Stamen and pistil, X 4. Organ Mountains.

FIG. 6. Leaf and spine, natural size. White Mountains.

FIG. 7. Fruit, natural size. White Mountains.

FIG. 8. Achenes, X 2. White Mountains.

FIG. 9. Three forms of trichomes, magnified.

Bulletin of the Torrey Botanical Club 25: 152-155 (1898)
A new Southwestern Rose
E. O. Wooton

(PLATE 335.)

* Bot Gaz. 22: 32. 1896.
The species here described and figured is particularly interesting as being the second member of a heretofore monotypic section of the genus Rosa—the Minutifoliae of Crepin.* While agreeing in most particulars with the characters there ascribed to this section, it can hardly be said to have appendiculate outer sepals, nor is the pubescence of the receptacle long.

While closely related to Rosa minutifolia Engelm., it is easily separated from that species by its less numerous and larger hips. with fewer and smaller spines. The stellate trichomes, referred to in the name I have given it, are most unique and interesting in this genus.

As an addition to the known wild roses it is of especial interest on account of the size and beautiful coloring of its flowers. It seems well worthy of cultivation.

ROSA STELLATA

Shrub, 4-6 dm. high, much branched. Stems stiff, beset with numerous straight or slightly curved yellowish spines, young stems closely covered with stellate trichomes which may be scale-like or have a central gland-bearing axis, or this axis may be a well developed spine: leaves small, 1-2.5 cm. long, 3-5-foliolate; leaflets triangular, 5-7 mm. long and almost as broad, cuneate, apex truncate or slightly rounded, cut into 5-8 large rounded but acute teeth, one sinus frequently reaching to the middle of the leaflet; stipules oblong, 5-7 mm. long, obtuse, spreading, adnate for about half their length, entire or with 1-2 rounded teeth; leaflets, petiole and stipules covered with a fine spreading silky white pubescence, not glandular: flowers large and showy, solitary, 4-7 cm. in diameter, terminal, deep rose-purple; pedicel short, 1 cm. or less long, stout; calyx-tube globose, 6-8 mm. in diameter, very finely pubescent and covered with numerous spines: pedicel, calyx tube and spines generally purplish tinged; limb of calyx ovate-lanceolate, 1.5-2 cm. long, 5 mm. broad at base, white woolly within, persistent and connivent in fruit, generally laciniately 2-3-lobed, lobes slender, broadened at apex, entire or serrulate, glandular along the margin; petals broadly obovate, 2.5-3 cm. long, 2-2.5 cm. broad, truncate, outer margin repand; stamens numerous, 5 mm. or less long; filaments slender, glabrous; anthers versatile, elliptical, with cordate-reniform base and emarginate or retuse apex, dehiscent by marginal slits, introrse; pistils many, 5 mm. long, covered with stout fuscous hairs; ovary short-stipitate, stipe attached at one side of median line; style rather stout; stigma capitate, oblique; fruit irregularly spheroidal, spiny, 1-1.5 cm. in diameter, reddish brown; achenes numerous, oblong or elliptic cylindrical, brown, glabrous.

First collected in flower near the Cueva in the Organ Mountains, New Mexico, April 30, 1893, on a dry rocky hillside at an altitude of about 5500 feet. Collected again at the same place with immature but dried up fruit July 10. 1297 (no. 126), and in the White Mountains, Lincoln County, July 22, 1897 (no. 193), two miles west of the Mescalero Agency at an altitude of about 6000 feet. A single specimen collected in August, 1897, on the Fresnal in the Sacramento Mountains, N. M., at an altitude of something over 6000 feet was kindly given to me by Miss M. C. Eaton, of Roswell, New Mexico, who told me that it was very abundant where she had found it, often forming large patches acres in extent and producing a beautiful appearance.

There is some considerable variation in the specimens collected at the different localities, those from the higher altitudes being more vigorous (generally 10-12 dm. high, with larger leaves), more glandular, more spiny and less pubescent The description above applies to the plant first collected except in the fruit. Specimens with ripe fruit from this locality I have not seen, but I have here described the fruit of White Mountain plants.

The Organ Mountain specimens are closely lepidote on all the branches of the year and these trichomes, which are not usually spiny, persist on branches that are two years old. The leaves are as described, finely pubescent and not az all glandular, and the leaflets perfectly triangular. Specimens from the White Mountains show all grades of stellate scaliness from closely so on the branches of the year, to only slightly so immediately below the flowering peduncles. Old stems are rarely lepidote and all are much more spiny, the stellate trichomes being replaced by numerous fine recurved spines. The leaflets of these specimens vary from triangular to obovate, and from finely pubescent to perfectly glabrous. The teeth are generally more numerous and the margin is more or less supplied with sessile glands.

The Fresnal specimen is perfectly glabrous on leaves and stems, but the stems are very spiny and bear numerous stipitate glands, while the margins of the leaflets and stipules are very glandular; the leaflets are usually five in number and obovate. The absence of stellate trichomes, the more numerous spines, the generally more numerous, larger, and differently shaped leaflets, and the glandular character of this plant would seem to be sufficient to establish a well marked variety at least, but the material examined seems to me to be too scanty to warrant such action.


Nature 90: 571 (Jan 23, 1913)
Rosa stellata
T. D. A. Cockerell
Boulder, Colorado, December 30, 1912

IN 1898 Prof. E. O. Wooton described a remarkable new rose from southern New Mexico, giving it the name Rosa stellata on account of the stellate trichomes. The peculiar, mostly trifoliolate leaves. the leaflets with cuneiform bases and more or less truncate, sharply toothed apices, gave the plant an unusual appearance; while even the flowers, described as "large and showy. . . deep rose-purple," were not at all like those of the ordinary wild roses of the Rocky Mountains. Through the kindness of my friend, Prof. Fabian Garcia, I obtained some living plants of R. stellata from the original locality in the Organ Mountains. Some of these were sent to Dr. A. R. Wallace, who has grown them in England successfully; the others have been growing in Boulder, Colorado. Last year the plants in my garden grew exceedingly well, and were most attractive. Certainly if R. stellata can be generally used in gardens, it will be a valuable addition to horticulture, but it probably will do its best only in relatively dry climates. My wife attempted crosses with several other roses, and in one case was successful in getting good seed; what will result remains to be seen.

The fruit of R. stellata, as indicated by Wooton, is large, beset with strong slender prickles. Quite unlike the usual types of rose fruits, its walls are dense, not at all fleshy or brilliantly coloured, but corky. The orifice is very broad, with a diameter of 8 mm. The bright chestnut-red seeds, about 4 mm. long, are long-oval, not compressed, and therefore not at all angular. All this differs conspicuously from the fruit of typical Rosa.

R. stellata, however, is not the only plant of this type. Years before, Engelmann described R. minutifolia from Lower California, a plant with the same general characters. In recent times, Dr. Greene has separated part of Wooton’s R. stellata as R. mirifica, and has added a fourth species, R. vernonii. Thus we have a compact group, which should, I think, form a distinct subgenus or genus Hesperhodos, with stellata as the type. All the species are of extremely restricted distribution, which may probably be explained by the fact that the fruits are not adapted to be eaten by birds.

The wide-open prickly fruit suggests that this may be a primitive form, as compared with true Rosa; but it is to be noted that the roses found fossil in the Miocene beds of Florissant, Colorado, belong to the true genus Rosa, not at all to Hesperhodos.