A REVISION OF THE NORTH AMERICAN SPECIES OF THE GENUS OXYTROPIS, DC.

BY ASA GRAY.

Communicated May 14th, 1884.

In the sixth volume of the Proceedings of the American Academy (1863), as an appendix to a revision of Astragalus, I made an attempt to classify and characterize our comparatively few species of Oxytropis. In the autumn of 1880, I compared our own materials with those in the Kew herbarium, but, unfortunately, without knowing of Bunge's Species Generis Oxytropis, which was communicated to the Imperial Academy of Sciences of St. Petersburg in November, 1873, and published in its Mémoires, Ser. VII. Vol. XXII., in 1874. Bunge cites my notes, but he had not the means for clearing up the obscurities. Even now, after some examination of most of the originals, I can only partially remove them. But the subjoined synopsis may fairly represent our present knowledge.

OXYTROPIS, DC.

§ 1. Caulescens, nunc subcaulescens; stipulis inter se et a petiolo liberis: legumen uniloculare calycem longe superans. Subgen. Phacoxytropis § Mesogææ, Bunge.

1. O. DEFLEXA, DC. O. foliolosa, Hook. (O. foliosa, in Torr. & Gray, Fl.), forma subacaulis. - Saskatchewan, and along the Rocky Mountains to S. Colorado. (N. Asia.)

§ 2. Acaulescens vel subcaulescens ; caudicibus multicipitibus conferte foliosis, stipulis petiolo adnatis: folia simpliciter pinnata.

* Legumen calyce fructifero ovato-globoso vesicario prorsus inclusum, ovatum, uniloculare: pedunculi debiles 1-2-flori. — § Physocalyx, Nutt. § Calycophysa, Gray, Proc. Am. Acad. vi. 234. Subgen. Physoxytropis, Bunge, Oxytr. 161.

2. O. MULTICEPS, Nutt. in Torr. & Gray, Fl. i. 341. Mountains of Wyoming, Nuttall, in fruit only.

Rocky

Var. MINOR. Pulvinato-cæspitosa, depressa; foliolis minoribus lin. 1-3 longis.-O. multiceps, Gray, Proc. Acad. Philad., 1863, 61; Proc. Am. Acad. vi. 234.- Alpine region of the Rocky Mountains, S. Wyoming and Colorado, Parry, Hall & Harbour, Vasey, Coulter, &c. Leaflets about half the size of those of Nuttall's original, and fruiting calyx rather smaller. No quite intermediate specimens have yet been found.

Legumen calyce fructifero repleto vel hinc fisso parum longius, turgidum, pubescens, sutura ventrali introflexa semi-bilocellatum: scapi folia superantes, capitato-pluri- vel pauci-flori: plantæ albo-sericeæ, spithamææ flores ultra semipollicares, bracteis majusculis.

Rocky

3. O. NANA, Nutt. 1. c. Pube adpressa argenteo-sericea; foliolis 3-4-rarius 6-jugis angusto-lanceolatis; corolla purpurea vel pallida; legumine turgido-oblongo subcoriaceo, apice acuminato e calyce fructifero tenuiter villoso distento sed integro parum exserto. Mountains of Wyoming, on stony hills along the branches of the Platte, Nuttall, Geyer, the latter under the name of O. multiceps in Hook. Lond. Jour. Bot. N. W. Wyoming, Parry, no. 91 & 90, along with a larger form, with the inflorescence in fruit sometimes oblong; the same collected by Dr. Forwood. S. Montana, S. Watson, who notes that the flowers are "deep pink." This may be O. argentata of Pursh. Fl. 473.

4. O. LAGOPUS, Nutt., Jour. Acad. Philad. vii. 17. Pilis laxioribus albo-sericea; foliolis 4-5-jugis lanceolatis vel oblongis; corolla læte violacea; legumine ovato subvesicario fere membranaceo obtuso stylo subito rostrato calycem villosissimum mox fissum parum superante. Rocky Mountains of Wyoming and Montana, Wyeth, Howard, Parry (no. 92), Greene, Scribner.

✶ ✶ Legumen basi tantum calyce aut integro aut hinc fisso suffultum,

Vesicario-inflatum membranaceum, ovatum, uniloculare: scapi vel pedunculi debiles, pauciflori, fructiferi mox decumbentes: herbæ

nanæ, caespitoso-depressæ. -§ Physocarpe, Gray, Proc. Am. Acad.

vi. 234.

5. O. PODOCARPA, Gray, 1. c. Villosa, mox glabrescens; foliolis 5-11-jugis lineari-lanceolatis (lin. 3-4-longis); pedunculis folia haud superantibus bifloris; floribus majusculis (lin. 7-8 longis); corolla violacea; legumine amplo (sæpius pollicem longo) lato-ovato puberulo brevi-stipitato, sutura ventrali intrusa. O. arctica, var. inflata, Hook. Fl. Bor.-Am. i. 146. O. Hallii, Bunge, Oxytr. 162, described from a specimen barely in flower, appears to be of this species. - Alpine and subalpine in the Rocky Mountains, from S. Colorado (J. M. Coulter, Greene, Brandegee, Hall & Harbour, &c.) to British America (Drummond, Burke, Bourgeau, Macoun); and from Labrador to the Aleutian Islands; but specimens from the latter not in fruit, therefore uncertain. The stipe of the legume is variable, sometimes very short, perhaps never quite equalling the calyx.

6. O. OREOPHILA. Sericeo-canescens; foliolis 3-5-jugis lanceolatis oblongisve (lin. 2-4 longis); scapis folia plerumque superantibus capitato-4-8-floris; floribus parvulis (lin. 4-5-longis); corolla ut videtur purpurea; legumine haud stipitato oblongo-ovato griseo-pubescente vix semipollicari, sutura ventrali subintrusa. Mountains of Utah (Aquarius Plateau at nearly 10,000 feet, L. F. Ward, in 1875), and on Grayback Mountain, San Bernardino Co., S. California, at 9,000-12,000 feet, W. G. Wright, Lemmon, in 1879-80.

A possible variety of this, or a related species, with flowers almost immersed in the tufts of foliage, was collected in Rabbit Valley, Utah, by Mr. Ward (no. 574), but only in blossom.

← ← Legumen obcompressum, lanceolato-oblongum, tenui-chartaceum, sæpius nigricanti-pilosum, suturis utrisque intrusis fere bilocellatum: pedunculi 1-2- (raro 3-) flori, breves vel brevissimi in caudicibus nanis foliosissimis.

7. O. NIGRESCENS, Fischer in DC. Prodr. ii. 278. Astragalus nigrescens (large form) & A. pygmæus, Pall. Astrag. t. 53, 54. — Arctic coast, especially on the Asiatic side; coll. by C. Wright on Arakamtschetchene Island within Behring Strait; and by J. Muir on Cape Thompson, on the American side.

Var. ARCTOBIA. Pumila, pulvinato-depressa, albo-villosa; pedunculis unifloris; pube calycis et leguminis aut griseo-albida aut nigra. O. arctica, var., R. Br. in Parry, Voy. O. arctica, var. minor, Hook. in Parry, 2d Voy. 396, & Fl. Bor.-Am. i. 146. 0. arctobia, Bunge, Oxytr. 114, excl. syn. Nutt. - Arctic sea-coast, coll. Admiral Parry and most later explorers. Evidently passes into O. nigrescens.

=

Legumen fere teres, turgidum, sæpius hinc sulcatum, chartaceum vel coriaceum: scapi sat elongati, 1-4-flori.

Foliola plurijuga: legumen angusto-oblongum, haud stipitatum, septo e sutura ventrali introflexo bilocellatum.

8. O. PARRYI. Sericeo-canescens; foliis scapisque 1-2-floris demum spithamæis; foliolis 7-9-jugis oblongo-lanceolatis lin. 2-3 longis; calyce brevi griseo-pubescente, dentibus tubo campanulato æquilongo: legumine (lin. 5-6 longo) hinc profunde sulcato pube brevi griseo.— Rocky Mountains of Northern New Mexico and Colorado, near the limit of trees, Parry, Hall & Harbour, Greene, with mature fruit in July flowers not seen. Was named by me O. arctica in Hall & Harbour's collection, no. 143, and O. Uralensis, var. pumila, in Proc. Am. Acad. vi. 235, and O. Lagopus, Nutt., was wrongly referred to it. From the references this would seem to be the plant described as 0. arctica by Bunge, Oxytr. 97, but his character does not accord with Hall & Harbour's specimens, which want the flowers, and are very different from Brown's plant (which I now know). It would seem that Bunge's description was drawn partly from Hall & Harbour's specimens, partly from Brown's character of O. arctica, and partly from that of O. Lagopus, Nutt., which I had very wrongly adduced to Brown's species.

== Foliola 4-6-juga, villoso-sericea: legumen ovato-oblongum, haud stipitatum, semibilocellatum, cum calyce sæpius nigricanti-pubescens : scapi folia superantes, capitato-2-5-flori.

9. O. ARCTICA, R. Br. App. Parry Voy. 278 (non 309); Hook. Fl. Bor.-Am. 1. c., excl. ß & S. O. Uralensis, var. arctica, Ledeb. Fl. Ross. i. 594. Probably also O. Uralensis, var. pumila, Ledeb. 1. c. — Arctic sea-coast, coll. first in Admiral Parry's voyage, also by Richardson and by later arctic explorers. Certainly not a form of O. Uralensis; the stipules destitute of the nervation of that species, having only a midnerve and one or two recurving veins. Plant quite unlike the forms of O. nigrescens and O. podocarpa, which have been referred to it.

=

Foliola aut 3-5, aut solitaria; legumen oblongo-ovatum, brevi-stipitatum, nigricanti-pubescens, sutura ventrali intrusa vix semi-bilocellatum: scapi folia superantes, 1-4-flori.

10. O. MERTENSIANA, Turcz., Ledeb., Bunge, Oxytr. 116. I have fruiting specimens of this from Arakamtschetchene Island, on the Asiatic side, within Behring Strait, collected by C. Wright. From my notes made in the Kew herbarium, I am disposed to consign to it, rather than to O. arctica, the specimens referred to the latter species by Seemann