Mentha sylvestris* auctt. himal.: Hook. f.
Very similar to the previous species and only differing in a combination of quantitative characters: generally more slender in habit, leaves usually narrowly oblong-elliptic, frequently discolorous, clearly or shortly petiolate (petiole up to 8 mm), spikes more slender with verticillasters generally separated and calyces usually 1.5-2 mm.
Fl. Per.: July-October.
Type: [NW India] Deyra Dhoon, J. F. Boyle (LIV? G).
Distribution: Afghanistan, Pakistan, Kashmir, NW India, Tibet.
There is no doubt that Mentha royleana, the commonest mint in our area, is very close to Mentha longifolio. Many authors have reduced it to varietal rank or totally subsumed it. A number of specimens (some are cited below) are intermediate. But the fact that a large number of specimens can be recognized on the combination of characters cited above, the different facies from the more western Mentha longifolia and the distribution pattern support its recognition at subspecific or specific level. And if a taxon such as the wild Mentha spicata is given specific status separate from Mentha longifolia, there are reasonable grounds for giving Mentha royleana a similar rank.
Rechinger recognized 3 varieties of Mentha royleana in Flora Iranian var. royleana (leaves white villous-pubescent beneath); var. detonsa (Briquet) Rech. f. (slender plant with thin leaves and elongated branches - the commonest variety) and var. afghanica (Murata) Rech. f. (sturdy with thick leaves). All 3 varieties were recorded from Pakistan, but only one or a few specimens of each were cited. With the fairly abundant material I have seen from Pakistan, I could not confidently assign our specimens to these varieties.
The subspecies hymaliensis Briquet of Mentha longifolia, or Mentha royleana, must be typified by Aitchison 620, but this specimen has not been traced (see also Rechinger, l.c. 568). Although Briquet did not cite the locality of the specimen, it was probably collected in the Kurram valley.
Some anomalous specimens (of which there are many) or specimens somewhat intermediate between Mentha longifolia and Mentha royleana are:
A-8 Gilgit: Naltar valley, Ghafoor & Z. L. Butt 812 (KUH); B-7 Hazara: Kaghan valley, coll. illeg. 263 (KUH); Swat: Ushu, Nasir & Siddiqi 984 (RAW); B-8 Gilgit, 1500 m, R. R. Stewart 26189 (RAW); D-4 Quetta: Hanna lake, Nazim & Iqbal Dar 295 (KUH).