Oreophysa: An Overlooked Genus of Leguminosae

Abstract

In 1843, H. F. Jaubert & E. Spach described a new species based on a herbarium specimen (Aucher-Eloy s.n., from mountains near Teheran in Persia). It was placed in Sphaerophysa DC. as Sphaerophysa microphylla Jaub. & Spach. The description of the species was accompanied by a very good, precise illustration of a leafy shoot in fruit, together with good enlarged drawings of leaf, calyx, dehisced fruit and seed. As the herbarium specimen lacked flowers, the authors placed the plant in Sphaerophysa mainly because of the shape and size of the fruit, which, at first glance, is reminiscent of that of Sphaerophysa salsula DC. Some twenty years later, G. Bentham (in Benth. & Hook. f., Gen. Pl.) mentioned this species and showed that it differed from the other species of the genus Sphaerophysa in having trifoliate leaves, few-flowered inflorescences and the style bent on top. In spite of such markedly distinct characters, he could not decide to place Sphaerophysa microphylla into a distinct genus. In 1872, E. Boissier (Fl. Or.), basing his decision on herbarium specimens (Kotschy 292 and Bunge s.n.), included Sphaerophysa microphylla in the genus Colutea, changed its name unjustifiably to Colutea triphylla and founded a monotypic section, Oreophysa Bunge ex Boiss., for this species. The shape of the style and the presence of characteristic swellings at the base of the standard were the basic characters used to refer it to the genus Colutea. As sectional characters Boissier mentioned the suffruticose growth, obovate shape of the wings and the small number of ovules. J. Bornmuller (in Bull. Herb. Boiss.) in 1905, and later together with E. Gauba (in Fedde, Rep.) in 1936, mentioned this species twice, but under the name Oreophysa triphylla (Bunge pro sectione Colutea). In giving a reference to Boissier, Fl. Or., where Colutea triphylla is placed in a section Oreophysa, it is clear that Bornmiuller intended raising the section to generic rank. Under Article 41, clause 2 of the 'International Code of Botanical Nomenclature' (I96i), this indirect reference to an effectively published description in a different rank validates the generic name Oreophysa, a name which has, not unexpectedly, been omitted from the 'Index Kewensis'. In I907, C. K. Schneider also considered Sphaerophysa microphylla not to belong to the genus Colutea. When revising herbarium specimens of Colutea he wrote 'Oreophysa genus distinctum videtur' on specimens of J. & A. Bornmuller 6626 in both the Geneva and Vienna University herbaria. Schneider also failed to described the new genus. In this way, both in herbaria and in literature, both names, Colutea triphylla (Buhse, 1899; Parsa, 1948; A. C. Trott in sched.) and Oreophysa triphylla (K. H. Rechinger, E. Gauba in sched.) are met with. This species, although similar to Colutea in some respects, is so distinct from all species of that genus (about 25) in a number of characters, that I agree with Bornmtiller in segregating it in the genus Oreophysa. The genus Oreophysa differs from the genus Colutea mainly in suffruticose growth, subdichotomous branches of the shoots, considerable length of internodes, reduced foliage, broad wings, shape of fruit, and presence of only 4