Finding Primula vaginata

Front row, seated from left to right: D.E. Holland, Ugyen Wangchuck, John Claude White, Thutop Namgyel and his consort Yeshe Drolma.
Type Location
According to the protologue for Primula vaginata in J. Linn. Soc., Bot. 20: 4. 1882 and repeated in Fl. Brit. Ind. iii. 484 , the type is C.B. Clarke s.n., La Ghep, alt. 10,000ft. in the Sikkim Himalaya. In W.T. Stearn’s gazetteer of the Ludlow & Sherriff expeditions to Bhutan and SE Tibet in 1933-1950, the alternate name for Laghep is given as Lagyap and the location is a place on the route between Gangtok and the Nathu La just before Tsongmo Lake.

The type collection for Primula vaginata was made in 1876, which was when Chogyal Thutob Namgyal was ruler (see image above) and before the capital was shifted from Tumlong to Gangtok in 1894. It was the tradition of the Chogyal to reside in Tumlong in the dry season and spent the monsoon season in Chumbi and the direct route between the two was via the Cho La. This was also before British movements (1903-1904) focused attention on the Nathu La and Jelep La and so the location given by Stearn doesn’t make sense.

If we look on the section above of this map there are two locations marked as Lapyap, one on the road to Nathu La and one on a ridge leading to the Cho La. Tracing the routes described in J.D. Hooker's Himalayan Journals and Gammie's "Botanical Exporation of Sikkim-Tibet Frontier", we can see that the obvious location is the one on the ridge going to the Cho La. Laghep is described as a stone hut on the ridge at 10,475ft. elevation, so my best guess is near 27°24'40.71"N 88°40'36.51"E.
Courtesy: Kew Royal  Botanic Gardens

P. vaginata leaf base
P. vaginata Characteristics
The defining characteristic of Primula vaginata is its vaginate leaves, which have a broad, sheath like base. This is quite evident in the images above from the wild and a portion of the herbarium sheet K000750413 from Kew Royal Botanic Gardens. 
Type locations
Two other species are described as being similar to P. vaginata. They are P. normaniana and P. eucyclia. Both of these species are from further East of P. vaginata, with P. eucyclia described as being mat forming, more slender and with fewer, but larger flowers, and P. normaniana described as being creeping with even larger flowers, crimson instead of violet flowers, shorter pedicels and flower heads much larger. Images from Arunachal Pradesh do show a slender form growing alongside a more robust form so there are variations within populations. The Flora of China regards all as subspecies of P. vaginata.


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