Primula pulchra - Hide and Seek with P. gambleana

In 1882, An article was published in the Journal of the Linnean Society titled "On some Undescribed and Imperfectly known Indian Species of Primula and Androsace" by George Watt. It was actually J.D. Hooker that wrote this article in Watt's name, using Watt's notes, though revising them where needed, and with the intention that this would be used in the Flora of British India that was being written at the time by Hooker.

Primula pulchra or not? (Smith collection)
The first new species of Primula described in the article is P. gambeliana (a spelling mistake of P. gambleana) from a collection (Watt 5483) made at "the Tra Cha Kumpa Kubra Rock (Black Kabur?) above Jongri (Dzongri), Sikkim 27°30'29.99"N 88° 9'9.45"E. It grows in moss and often in crevices of steep wet cliffs.

P. pulchra is the second new species described in the article, from a collection (s.n. 12,000 ft) made by Hooker at Lachen, Sikkim (27°43'2.18"N 88°33'29.02"E, probably in the Zemu valley according to Hooker's Himalayan Journals). Also noted is a syntype collection (Watt 5406) made at the upper Ratong Chu Basin, Jongri (27°32'38.68"N 88° 8'4.47"E) for which Watt 5268 is given as equivalent. This location is very close to the type location for P. gambleana.

Both of these species are figured: P. gambleana - Tab I, and P. pulchra Tab II. A (see image below). Hooker makes the comment under P. gambleana in the Flora of British India: "petiole not sheathed at the base as in P. pulchra, which this a good deal resembles".
Drawings from the Journal of the Linnean Society
If you compare the two drawings side by side, there are a lot of similarities between the two species. Both having a sheathing base, but the scales are much larger in P. pulchra. The most obvious difference is the leaf shape with the leaves of P. gambleana shown as orbicular though Smith & Fletcher later described them as "ovate-cordate or ovate-oblong rather than orbicular" and noted that the figure shows the leaves as more orbicular than is usual. The leaf base is described as usually deeply cordate but occasionally truncate. Smith & Fletcher describes the leaves of P. pulchra as oblong to ovate-oblong with a rounded or slightly cordate base. Both species are shown with an obvious scape with 1-10 flowers. The relative size of the plants on the types specimens are similar.
P. pulchra? capsule (L), P. gambleana capsule (R)
courtesy Royal Botanic Garden Edinburgh
Apparently, the most distinguishing feature is the seed capsule which was not known when the two species were described. P. gambleana has a cylindrical capsule, twice as long as the calyx and dehiscing by longitudinal valves. Seen in only one collection of P. pulchra (Tari, Sikkim, no collector) at Edinburgh is a subglobose capsule equalling the calyx dehiscing by a crumbling wall (Section Petiolares type). This collection is of 6 thin, sparsely flowered plants, and none show the sheathing base that is seen in similar plants in the type collections. Is this really P. pulchra in seed or is it another petiolarid species?
Primula sp Yak Desha = P. pulchra Smith?
In about 1985, George Smith made a collection from the area near Kanchenjunga that was identified as P. pulchra. It was awarded a PC in 1991 and may still be still in cultivation. This clone does not seem to produce the tall scapes of the type collection and it makes me wonder if it really is P. pulchra. In addition to this is a recent image from Yak Desha, Nepal which seem to equate to the Smith collection but again does not seem to be the same as the type collection of P. pulchra!

Perhaps the Smith collection is true P. pulchra, but it is important to get it right because it affects other related species P. chamaethauma and P. chamaedoron which have been lumped into P. pulchra by some authorities.

What is needed is lots of images, including the capsules, of both P. pulchra and P. gambelana from Sikkim in the Ratong basin (near HMI Base Camp) and the cliffs around Black Kabur, near Dzongri. Only with this additional information can this puzzle be solved. If you can help, please contact Pam Eveleigh.

Pam Eveleigh © 2017


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