Leaflets of Botanical Observation and Criticism, 1910 pp. 60-64
Edward L. Greene

Certain American Roses

In the course of two thousand years' history of the genus Rosa perhaps no more remarkable taxonomic discovery was ever made than that which fell to the lot of Dr. C. C. Parry and his party in 1882, when, botanizing along the seaboard of the Mexican Territory of Lower California, they came upon that unknown shrub which Dr. Engelmann soon after published as Rosa minutifolia.

In general appearance that shrub is far removed from all other roses that were then known, insomuch that I much doubt whether such experienced botanists as those discoverers were would have seen in it a member of the genus Rosa at all, if the bushes had been devoid of all traces of buds, flowers or fruits; for it is only by its answering, as to flowers and fruits, to the artificial phytographic technicalities which are allowed to be definitive, that Rosa minutifolia is admitted to that genus.

During some fifteen years this Lower Californian curiosity remained practically a monotypic subgenus. Then in 1897, not much less than a thousand miles inland from the Mexican seaboard, Mr. Wooton discovered in the mountains of New Mexico, at elevations of 5,000 to 6,000 feet, what he regarded as a second member of this strange group, and he published it as Rosa stellata. There are contrasts more pronounced than have hitherto been indicated between the Lower Californian shrub and that of the Organ Mountains in New Mexico. Let us indicate these somewhat formally.

R. minutifolia. Young twigs with sparse and short pubescence: larger spines not much dilated at base, of dull color and notably pubescent: leaflets 5, not crowded, but the pairs equidistant: stipules with narrow subscarious body and divaricate foliaceous auricles.

R. stellata. Young twigs with copious stellate pubescence: spines much dilated at base, glabrous, white, polished: leaflets mostly 3, crowded at end of short rachis: stipules with very narrow body and ample foliaceous auricles divergent.

The excellent specimens of R. stellata distributed by Mr. Wooton are from two separate and rather well isolated mountain ranges in southern New Mexico, and he has noted clearly enough some of their divergences in his paper on them (Bull. Torr. Club, XXV, 152). Nevertheless, I seem to see that the discoverer of the New Mexican shrubs, in his diagnosis, has been betrayed by those curious trichomes of this type into the making of a synthesis which, on the whole, can hardly meet with general approval among students of roses. In other words, the Rosa stellata of the Organ Mountains and that of the Sierra Blanca are so very different in characters of stem, spines, leaves and indument that, on principles well established among rhodographers, they must be held specifically distinct. No expert in the knowledge of roses, contemplating figures 3 and 6 of Mr. Wooton's plate (Bull. Torr. Club, t. 335) would say that those two leaves, if taken from two plants from different regions, or even from the same hillside, are of the same species. The leaflets of one leaf are 5 and cuneate-obovate, notched all around the upper part from the middle or even from below that. Those of the other leaf are 3 only, each being exactly triangular, notched only across the line of the truncate summit. The stipules also of the two are constantly very different. But it will be profitable to make exact diagnoses of these two plants; and first of all, there needs to be given a fuller statement of the characters of the typical Organ Mountain plant, to which alone, as the specimens before me seem to show, the name chosen applies.

R. stellata, Wooton (restricted). Stems when growing scarcely armed with other than white broad-based white prickles, but hoarily stellate-tomentose by trichomes radiating around a low murication or obsolete prickle: leaflets of the very short leaves mostly 3, sometimes 4 or 5, all alike triangular, entire on two sides, deeply toothed across the truncate summit, pubescent on both faces, also closely and minutely somewhat pustulate-roughened above; stipules proper very short, surpassed by their large foliaceous auricles.

The contrast between this and the shrub of the White Mountains (or Sierra Blanca, as the name of that range ought always to be written) may be shown by a diagnosis of its stem and leaves quite as brief as the above. I shall call it

ROSA MIRIFICA. Growing stems light-green without stellate or any other hairiness, the few stout white prickles supplemented by very many intervening short almost filiform recurved and gland-tipped prickles: leaflets more commonly 5, of at least twice the size of those of R. stellata, strongly cuneate-obovate, strongly crenate-serrate around the obtuse apex, glabrous on both faces, not in the least pustulate or roughened; stipules long, wholly herbaceous, their small divergent or subfalcate auricles not notably foliaceous, the whole stipule marginally beset with small sessile glands.

This account of the leaves of the Sierra Blanca rose does not quite harmonize with the figure above referred to; for the figure shows leaflets more obovate and less cuneate, and with sharp rather than obtuse teeth, an indentation that could not be called crenate-serrate. But such as I have described here are the leaflets on two good sheets, one in the National Museum, and one in my personal herbarium, both as collected by Mr. Wooton in the Sierra Blanca.

There is now before me a third representative of this strange group of roses, and this from a region to the southward of New Mexico, taken by a zoological traveler in another isolated range, the Guadalupe Mountains of Texas. In compliment to the discoverer of it, I name the species

ROSA VERNONII. Next of kin to true R. stellata but growing twigs, also the peduncles, appearing retrorsely villous-silky; large spines more slender than in any of the foregoing, also not notably dilated at base, conspicuously deflexed, white and polished, numerous stout but short gland-tipped hairs or bristles intervening; leaves nearly all trifoliolate, glaucescent, nearly glabrous, faintly pustulate above leaflets notably dissimilar, the terminal much the largest and cuneate-obovate, the small laterals not cuneate but obliquely oval, all deeply crenate almost all around, the crenatures broader than high and themselves glandular-dentate; calyx closely villous-hirtellous, also armed with a few stout prickles.

Known only as collected in the Guadalupe Mountains, Texas, by Mr. Vernon Bailey, 15 Aug. 1901, the specimens in flower.

Old twigs of this rose show a roughness made up of short stout points, quite as in R. stellata, and the whole secret of the villous appearance of its pubescence is this, that the trichomes are developed here on only the lower or earthward base of the short prickles, and these are so crowded that the hairs, somewhat elongated, overlap.

I append characters of another new rose from the far Northwest.

ROSA ALCEA. Dwarf and apparently compact, the branches, and especially the flowering twigs copiously spinescent, the spines all rather slender, straight, ascending, or on older branches the larger and more persistent almost divaricately spreading, but none deflexed or even recurved: leaves small, of about 7 or 9 leaflets, these obovate, obtuse, closely serrate, green and nearly or quite glabrous above, glaucescent and soft-pubescent beneath; stipules broad and short, the petiolar vein beneath with a few firm spines, their margins more or less glandular-ciliate flowers solitary, the short petiole sparsely armed with gland-tipped spines; calyx-tube with not a few stout sharp spreading spines, but sepals quite densely glandular-prickly; corolla large, the petals obcordate.

Species known only in good flowering branches collected at Moose Jaw, Assiniboia, by Mr. William Spreadborough, in June, 1892, and communicated to me by Mr. J. M. Macoun. The Canad. Survey number is 10,624.

The type of my R. Macounii (Pitt. iv. 10) is also from Assiniboia, but is very different from this.