Mentha royleana

Mentha royleana is known by the English common name of Royle's mint, named for British botanist John Forbes Royle.[4][5] In Pakistan, it is referred to as Jangli podina[6][7] or simply podina or pudina.[8] Other attested regional names include:

• Kala podna[9]
• Nari Wailani (Pashto)[10]
• Safaid podina (Hindko)[11]
• Pahari pudina[12]
• Tulasi paate[4]
• Valenay (Miandam area)[13]
• Venalay[9]

Mentha royleana resembles other Mentha species, in particular Mentha longifolia. Like other mints, M. royleana is a perennial plant, reproducing via rhizome, and shares the pungent mint aroma of most of the genus.[2]

It is distinguished from its close relatives by its narrowly oblong-elliptic mostly petiolate leaves, which tend to be discolored.[14] Other authors attest the leaves can occasionally be sessile.[1] Its spikes are more slender, with separated verticillasters and calyces measuring 1.5 to 2 millimeters.[14] Its flowers are small and whitish in color.[4] According to a 2011 study, M. royleana contains a mean 179.2 milligrams of caffeic acid, 46.93 milligrams of rosmarinic acid, 41.76 milligrams of ferulic acid per 100 grams of plant material.[15]

The Mentha species in general demonstrate a large amount of genetic variation and ease of hybridization, which has made taxonomic distinctions a fraught question.[16][17] In a 2018 analysis, samples of M. royleana from different geographic regions of Pakistan demonstrated the greatest amount of genetic variability among the studied Mentha species.[18] As a result, several varieties have been defined. A 1992 study identified two varieties: var. glabra and var. gilgitica.[16] Botanist Karl Heinz Rechinger recognized three varieties in 1998: var. royleana, var. detonsa (Briquet) and var. afghanica (Murata).[14] A 2018 comparison of random amplification of polymorphic DNA markers differentiated three varieties of M. royleana: var. afghanica, var. royleana, and var. tugidus.[19]

The similarity of M. royleana to other mints has led some authors to even assign it as a mere varietal of M. longifolia.[20][14][2] However, it is currently accepted as a distinct species by authorities such as Plants of the World Online.[21] Studies of populations of M. royleana and M. spicata determined they were genetically distinct enough to justify their separate species classifications.[22] Recent literature continues to call for further investigation to establish M. royleana's true taxonomic status.[23][17]

While Mentha royleana's native distribution is in the region of the Himalayas (including India, Pakistan and Nepal), it is now established throughout Northwest Asia and Europe.[9] It has also been intentionally cultivated in parts of China.[2] It is frequent in wet places, principally at elevations from 9000 to 11000 feet[24] (11,000 or 12,000 feet in another source [25]). Some authors have described it as common,[13] or indeed even "the commonest mint" in Pakistan.[14]

Mentha royleana has been assessed as a plant with a "high use value" in traditional medicine.[26] It has been used to treat a variety of ailments. It is said to be used as a treatment for vomiting, diarrhea, dysentary, and cholera, as well as a general carminative.[27][3][28]

In the Margalla Hills, part of the Himalayan foothills, it is ground with the fruit of Zanthoxylum armatum and combined with salt as a stomach ache cure.[7] Herbal medicine practitioners in Batakundi mixes the leaves of M. royleana into green teas, with cooling and gas relief properties.[8] In Parachinar, the leaves of the plant are sewed into cloth pads and wrapped around babies' chests to relieve flus and chest problems.[10] In the Haramosh valley in Gilgit District, M. royleana is combined with pomegranate, ginger and garlic to produce a juice intended to treat diabetes and heart issues.[29] Combined with Thymus linearis (Himalayan Thyme), it is used to treat high blood pressure and abdominal worms.[29]

Aside from medical use, M. royleana is used to freshen the breath and in the preparation of sauces and salads.[30] The floral shoots of M. royleana are also used in religious ceremonies in Hinduism.[31]

• Data related to Mentha royleana at Wikispecies