A Christmas tradition in my family is to put together a jigsaw puzzle, but I have been working on a “Primula puzzle” too. Using various documents including "A Quest of Flowers" by H.R. Fletcher, "
The Gazetter of Ludlow and Sherriff Localities" by W.T. Stearn, field notes and diary entries, I am piecing together the route of Ludlow & Sherriff’s expedition of 1934 which started and ended in Bhutan, but also crossed over into what is now Tibet and Arunachal Pradesh (South Tibet). This involves a fair bit of sleuthing to find old routes and passes with just a few clues from the old documents.
Using the tilt feature in Google Earth helps to find passes which are usually located at the lowest point on a ridge and I grab the image and “push it” so that it moves and this gives the eye a better chance of spotting the scars of trails. In the dry Tibetan zone, routes haven’t changed and there are few new roads. The landscape is dominated by dirt and screes which show the trail scar very well so even if I lose the trail I can pick it up further on and then backtrack.
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| Trails can be easy to find in the dry zone |
It is more difficult to locate the route in wetter zones which are covered in dense forest and where the population is greater and new roads abound. However locating towns where Ludlow & Sherriff stayed and then carefully looking between those points can show the scars of old trails where the new forest growth is a different color to the old growth.
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| Scar of old trail through the forest |
Along the route I add markers for the Primula collections they made. These can then be linked back to actual herbarium sheets though most aren’t online, unfortunately, unless they are type collections. Doing the same for Kingdon-Ward’s route of 1935 detailed in “Assam Adventure” shows an overlap of the two routes in the region of western Arunachal Pradesh (South Tibet) between the Chera La, heading north up the Tulung Chu valley to the Tulung (Trulung) La where the routes part shortly thereafter. This valley is of great interest to me because here Kingdon-Ward found P. calderiana (purple flowered) lower down and P. strumosa (yellow flowered) higher up. It is this altitudinal difference which is noted in the
Flora of China as being a reason for keeping the two species separate rather than combining P. strumosa as a subspecies of P. calderiana as John Richards has done. Where the two species meet there are hybrids of various shades (see
species gallery under both species for hybrid images) and I will be investigating the relationship between these species further in the future. Sherriff only notes that he found a petiolarid seed capsule in this valley, which could come from either species (see the
species gallery under P. calderiana to see what this seed capsule would look like).
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| P. calderiana (L), hybrid, P. strumosa (R) |
There are lots of interesting bits of information noted by Sherriff including his expectations for where he thought they would find a greater variety of plants. "Dongkar is quite definitely in the Tibetan dry zone. But two miles down stream one meets the Tsuk Chu, and that valley shows the beginning of the "Transition Zone". There are dwarf rhododendrons and also some ordinary, if small rhododendrons too. Then at the Cha La we were still in the sun on the North side, while from the south a sea of cloud and mist was being blown up. It topped the pass and then seemed to fade away. Immediately we crossed the pass we knew we were in a good place for flowers." At the Cha La, they found P. littledalei (which was new to them), P. bellidifolia and P. eburnea.
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| The "Transition Zone" |
Once I have completed the route, it will be appended to this post as an image. And here it is...
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| Ludlow & Sherriff's 1934 Route |
Merry Christmas!
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