QBARS - v9n2 Occurrence of Rhododendron Species in Bhutan Collected By R. E. Cooper In 1914 And 1915

Occurrence of Rhododendron Species in Bhutan Collected By R. E. Cooper In 1914 And 1915
By R. E. Cooper

The following paper by R. E. Cooper tells of his expedition to Bhutan in 1915. "The Rhododendron Handbook" does not carry the field numbers of this expedition. Though forty years have elapsed since the expedition, both the article, by Mr. Cooper and letter by the late Sir Isaac B. Balfour, Regius Professor of Botany, Edinburgh, to Mr. Cooper should still be of great interest. The Society is indebted to Susan Worthington, editor of the Quarterly Bulletin of the American Primrose Society for the loan of the original Balfour letter and the article by Mr. Cooper.- Editor

Sikkim is famous as the earliest home of Rhododendrons and eastward, across the Chumbi Valley which lies along Sikkim's eastern border, is a strip of similarly mountainous country called Bhutan.
Bhutan covers the southern slopes of the Himalayas for about 300 miles, and stretches a phalanx of valleys and spurs south for 50 miles from the clusters of snow peaks on the main chain, to the dooars of Bengal.
There are three regions - the western valleys running south from the big cluster of peaks dominated by Chumolhari; the central valleys whose heads ramify from a cluster of peaks due north of Punakha; and the eastern valleys which lie in the shelter of another set of huge snow peaks guarding the gap in the Himalayas through which the Kuru Chu flows from Tibet into India.
The lowest elevation at which any rhododendron was found, was in red sandy soil, beneath Pinus longifolia forest, at an elevation of 3000 feet; in the valley of one of the eastern streams, the Kuru Chu. The species being the common R. arboreum , and not likely to be hardy, was not collected but merely noted. The highest growing species was R. setosum , which ranged above 15,000 feet. A companion species, outstripped only in the last few hundred feet nearer the snows, was R. nivale . This may now be seen growing in the Edinburgh Botanical Garden (Rock Garden), the only plant in cultivation from the highest growing species.
Certain species were common throughout Bhutan in similar conditions. The lepidotum , setosum , and anthopogon , are found on the land above tree-level; the campanulatum and virgatum in the highest forests of spruce, birch, and juniper; the grande , triflorum , and edgeworthii in the lowest regions to have snow are the plants not hardy in this country except in favored spots, the arboreum and dalhousiae .

Rhododendron setosum
Fig. 20.  The dwarf alpine Rhododendron setosum
among Himalayan Snows - Bhutan 1916
Cooper photo

Between the lowest record from 3000 feet and the highest from the vicinity of 16,000 feet there grows a set of plants whose altitudinal habitats are indicated in the accompanying tables.
Of the three regions, the western valleys have a similar distribution of high elevation flora to their neighboring valleys of Sikkim. There is the scattered occurrence of arboreum and maddenii at the first definite change of the vegetation from the subtropical to the sub-temperate indicated by the appearance of oaks and magnolias. A little higher, big clumps and thickets of tall growing grande and hodgsonii appear in moist mossy forest. At the first appearance of moist conifers - Abies as opposed to dry conifers, pines excelsa - the tall and often moss-covered species of rhododendron thin out, and drifts of cinnabarinum , wallichii , wightii , and campanulatum appear in the undergrowth. The bush forms of campanulatum and wightii reach to the first, open hillsides which the tree forms have declined to clothe, but here they prefer the sheltered slopes.
Ranging above even the sheltered slopes and adorning the rounded turf clad crowns of the lower ridges that look out over the deep valleys, and are in turn overlooked by the high and aloof, rock and ice pinnacles of the mountain-tops, are the dwarf bushes of the species of nivale , setosum , lepidotum , and anthopogon . These form continuous stretches on the first low moors, but plants of these species are driven gradually with increasing elevations-to seek the hollows, and finally to live their life in the shelter provided by the gaps between big boulders of the moraine.
A definite feature of the covering of the highest treed and shrubby slopes in the valleys of Bhutan is the occurrence of any species at higher elevations on the south-east facing exposures than on any other.
On the timber line of the slopes of a rising valley that lifts its head to the primula-studded moors, grey screes, and glittering snowfields, spruce forest will be seen running thin. The trees, getting more and more scattered and dwarfed, will be seen, however, growing on eastern slopes several hundred feet higher than on the slopes across the valley, which may have only a few scattered junipers.
The development of Rhododendron species, which from being shrubs under trees become full light bearers through the fading away of the tree forms, follow similar lines.
R. campanulatum , cinnabarinum , and wightii develop a continuous covering to the hillsides, draping the slopes and old moraines into graceful sweeps and contours of verdure in a most pleasant fashion. Gaps in the mantle there are, usually due to water logging of the soil, where a sort of fairy ring may be decked out with primulas; or a terrace covered with the meandering waters of a small spring will provide a contrast with clumps of Allium and Primula , both sikkimensis , rising from the grey slabs of rock half immersed in the water.
In the region of anthopogons such wet terraces are populated with Prim. involucrata , while Primula sapphirina will stud with blue, any peat nodules that may be about.
The Central Valleys are the uppermost reaches of the valleys north of Punakha and Tongsa. The folk who live in these valleys are able, by withdrawing bridges from the few places there the precipitous cliffs allow descent to the water's edge, to keep out would-be visitors from the south.
The people themselves visit the capital to pay tribute during the winter when the streams are no longer swollen by the summer rains or melting snows and can be forded. A visit to the upper reaches meant a more elaborate outfit than I could carry, and was therefore abandoned.
Each valley was partly penetrated, however, one to 9000 feet, and the other to 5000 feet, but the area was not particularly profitable.
Tongsa's Valley was not visited, but the next valley to it was traversed throughout. This was Pumthang, and although it is included in the eastern valleys, this valley gave an excellent indication of what was across the ridge. The ridge flora was poor and uninteresting.
The eastern valleys yielded R. thyodocum from 12,000 feet, argipeplum from 10,000 feet, and kendrickii from 8000 feet, as the most interesting records of new and rare plants in a region where the disposition of the common species of the genus became similar in quantity and range to the western valleys.
So much for the general range and the extremes of the genus ranging up the valleys.
The valleys of Bhutan develop an arid tendency in places, usually about elevations of 7000 to 9000 feet, where 1 he hitherto steep-sided gorges from the south open out to wide valleys. The majority of the inhabitants live in these places, and the air being dry and the soil reddish and sandy, pines - P. excelsa - are the greater wear for the surrounding slopes up to certain limits. Connecting these habited areas of the valleys, a track traverses the country from east to west, crossing the dividing spurs at elevations about 10,000 feet. There seems to be something about the elevation of 9500 feet which induces rain, because in the most arid and pine-clad valleys, a moist flora develops at this elevation on the side hills. This means that the tops of the ridges separating valleys are crowned with moist forest, and in this rhododendrons, of course, are found.
Interesting records include brachystphon at 7000 feet, epapillatum at 6000 feet, keysii at 8000 feet, dalhousiae at 6000 feet, maddenii at 7000 feet, polandrum at 8000 feet, vacinioides at 9000 feet, and such epiphytic species as rhabdotum at 9000 feet, and cooperi at 9000 feet.
That the arid valleys have no effect on the range of species may be judged from the list showing the occurrence of species in the eastern, central, and western valleys.
A feature of the distribution of Rhododendron species in Bhutan was that as in Sikkim, the greatest quantities of these plants are found on the east and south-east aspects of the main Chola groups; so in Bhutan, much more rhododendron country was found south-east of the big Chumolhari group and the big group of snows which, according to the map, lies north of Punakha, and another big group by the gap through which the Kuru Chu flows.
Of species newly discovered but not necessarily in cultivation, there 1S haemonium , a dwarf shrub of the anthopogon type from the higher moors of 13,000 feet, with yellow flowers, found only in the western valleys, and two other high elevation plants - R. thyodocum , a 3-foot sprawling bush with purple flowers from 13,000 feet, and R. argipeplum , a 6-foot bush from 11,000 feet, with red flowers remarkable for a mass of white hairs in the open throat. These last two are only found in the eastern valleys.
R. papillatum is a 6-foot bush from the spruce forests of the western valleys of 11,000 feet, bearing pale-cream flowers frilled at the edges, with a blood-red blotch in the throat and scattered pink spots on the lip. R. kendrickii was only found in fruit at 9000 feet, but was effectively decorative through the crinkled edges of its long narrow leaves; looking more like a holly than a rhododendron.
R. rhabdotum was the showiest of the whole set both new and old. A 12-feet bush growing on dry rock faces, the flowers look very like a cross between a R. dalhousiae and an Ipomoea from the reflexed rim of the trumpet and the red lines running down the outside of the corolla tube to the peak of the petals. Found growing at 8000 feet, it would be hardy only in the south of England. Only one collection of this plant is on record, and that was in flower, so that it has yet to be introduced and established.
Taking Hooker's note on the journey to the Chola Pass in November 1849 of the order of ascension of Rhododendron species in the Sikkim hills, it is found to be very applicable to the range of the species on the Bhutan hills.

At 6000 feet in Sikkim.- dalhousiae , camelliiflorum , arboreum , vaccinioides , adding for Bhutan-- brachysiphon , griffithianum , epapillatum , polyandrum .

At 8000 feet in Sikkim.- grande , argenteum , falconeri , barbatum , edgeworthii , campbelliae , niveum , adding for Bhutan - argipeplum , kendrickii , cooperi, keysii , smithii , rhabdotum , vaccinioides .

At 10,500 feet in Sikkim.- lanatum , virgatum , campylocarpum , adding for Bhutan - ciliatum , hodgsonii , campanulatum .

At 12,000 feet in Sikkim.- lepidotum , fulgens , wightii , anthopogon , setosum , adding for Bhutan - thyodocum , haemonium , triflorum , obovatum , elaeagnoides , nivale .

R. griffithianum in the Rydak Valley, Bhutan
Fig. 21. R. griffithianum in the Rydak
Valley Bhutan. The classic locality of this
first finding described by William Griffith.
Plant 20-25 ft. high on a dry sloping bank
of a stream.
Cooper photo

Has the direction or moisture content of the wind anything to do with higher ranging on certain definite slopes? Does the bedding of the rock belts which are tilted in one direction throughout the country affect the soil's composition and consistency? Who will venture an opinion when it is known that the winds travel up the valley and hillside for most of the day, and blow down the high slopes from the snows during the night? I can only testify from bitter experience that the air on these high slopes throughout the growing season for plants, from May to September, is a succession of blanketings of mist, sleet, and heavy rain, hastening before or with, bitterly cold winds.
The angle of dip of the rock beds is about 30 degrees to the north-west, the beds running north-east to southwest. This brings the broken ends of the strata on to the east facing or western side of the valleys, and those seem to be better for growing plants than the full rock face that underlies the thin layer of debris on the eastern slopes.


The most interesting plants in cultivation at Edinburgh are Nos. 1805 obovatum from 13,000 feet, 2224 thyodocum of 14,000 feet, 2148 lanatum of 12,000 feet, 3482 setosum of 15,000 feet.
3483 nivale of 15,000 feet, 3485 anthopogon of 13,000 feet, 3492 wallichii aff. of 12,000 feet, all alpines and rock-garden plants.
R. nivale grows happily and well, producing quantities of flowers every year in the Edinburgh Botanic Garden (Rock Garden), where it is grown on top of a ridge exposed to all winds except those from the south-west (Edinburgh's most severe wind to plant growth if the prevailing slant of trees is any guide). This aspect will suit all the high elevation plants.
The other numbers included 2088 hodgsonii from 10,000 feet, 2315 and 3615 griffithianum of 6000 feet, 3505 thomsonii of 10,000 feet, 3506 cooperi of 9000 feet, 3507 smithii of 7000 feet, 3541 triflorum of 9000 feet, 3588 virgatum of 9000 feet, 3601 brachysiphon of 9000 feet, 4978 kendrickii of 9000 feet, and 2922 a cinnabarinum which has produced yellow flowers, all requiring protection in the winter, except in the warmer counties and exposures.
The numbers which have been referred to as affinities of campanulatum , cinnabarinum , and arboreum are from plants which seemed to show sufficiently distinct variation in the field to warrant collecting.

Paro and Timpu
Punaka and Tongsa
Pumthang and Kuru Chu
15,000 ft. setosum, nivale
14,000 ft. lepidotum, campanulatum elaeagnoides, thyodocum, lepidotum
13,000 ft. setosum, lepidotum, wallichii, anthopogon, fulgens, haemonium, wightii, obovatum, campanulatum, thyodocum, campylocarpum, triflorum campanulatum, thyodocum
12,000 ft. lepidotum, virgatum, wallichii, lanatum wallichii, campanulatum, setosum, thyodocum, cinnabarinum, fulgens, lanatum
11,000 ft. barbatum, cinnabarinum, lepidotum, campylocarpum argipeplum
10,000 ft. cinnabarinum, pendulum, epapillatum, barbatum, arboreum, campanulatum, virgatum, thomsonii, cooperi, camelliiflorum, smithii, keysii, hodgsonii grande, barbatum, cinnabarinum, smithii hodgsonii, arboreum, thomsonii argipeplum, lanatum
9,000 ft. virgatum, triflorum, barbatum, maddenii, grande, falconeri edgeworthii, virgatum, argenteum, keysii, rhabdotum, cooperi, vaccinioides, grande cooperi, kendrickii
8,000 ft, arboreum, keysii, polyandrum, virgatum griffithianum, grande salignum, griffithianum
7,000 ft. arboreum, maddenii, griffithianum, virgatum, smithii arboreum, brachysiphon, maddenii
6,000 ft. arboreum, maddenii, brachysiphon, griffithianum, dalhousiae, epapillatum dalhousiae, grande
6.7.1914 Timpu Valley 6,000 ft. 1291 arboreum
6.7.14 "         6,000 ft. 1292 maddenii
8.7.14 "         8,500 ft. 1454 polyandrum, Hutch New sp. 3 ft. bush, white flrs.
8.7.14 "         8,500 ft. 1456 keysii aff. 4 ft. bush, tubular orange flrs.
12.7.14 "         8,500 ft. 1516 virgatum aff.
13.7.14 "       13,000 ft. 2552 lepidotum Dwarf
13.7.14 "       12,500 ft. 3064 virgatum On west side ridge
15.7.14 "         7,000 ft. 1545 arboreum aff.
15.7.14 "         8,000 ft. 1547 virgatum
16.7.14 "         9,000 ft. 1575 arboreum
24.7.14 Philey La., India 13,000 ft.
-Tibet divide
1805 obovatum aff. Flrs. purple, 4 ft. bush
26.7.14 Timpu Valley12,000 ft. 1937 cinnabarinum In fruit, only 10-15 ft.
27.7.14 "       12,500 ft. 1960 campanulatum 3 ft. bush, with brown under leaf, flrs. light to dark purple
28.7.14 2590 wightii
28.7.14 "       13,000 ft. 2592 campanulatum
29.7.14 "       10,000 ft. 2928 thomsonii
29.7.14 "       10,500 ft. 3256 cinnabarinum
29.7.14 "       10,000 ft. 3257 smithii
30.7.14 "       10,000 ft. 2475 arboreum in fruit only
30.7.14 "       12,000 ft. 2489 wallichii. aff.
30.7.14 "       10,000 ft. 2503 wallichii
30.7.14 "       10,000 ft. 2504 campylocarpum aff. if flowers yellow
30.7.14 "         9,000 ft. 2505 hodgsonii
30.7.14 "       10,500 ft. 2581 cinnabarinum
4.8.14 "       13,000 ft. 2490 setosum
5.8.14 "       13,000 ft. 3233 campanulatum
5.8.14 "       13,000 ft 3234 wightii, Don
5.8.14 "       13,000 ft. 3235 thyodocum
5.8.14 "       13,000 ft. 3236 lepidotum
5.8.14 "       13,000 ft. 3238 wallichii aff.
6.8.14 "       10,000 ft. 2922 cinnabarinum A plant raised Bot. Gard., Edin., from seed under this number has proved to be R. cooperi, but must be an odd escaped seed
6.8.14 "      10,000 ft. 2924 arboreum
7.8.14 "      10,000 ft. 2648 camelliiflorum aff.
8.8.1914 Timpu Valley
10,000 ft.
3346 virgatum
10.8.14 "     10,000 ft. 3383 keysii
11.8.14 "       9,000 ft. 3423 maddenii
13.8.14 "     12,000 ft. 2523 lepidotum
24.8.14 Upper Mo. Chu
9,000 ft.
(Punakha) Valley
2756 edgeworthii
24.8.14 "       7,500 ft. 2760 arboreum, Sm.
26.8.14 "       9,000 ft. 2903 arboreum, Sm.
26.8.14 Mo Chu Valley
9,000 ft.
3151 virgatum
27.8.14 "       7,000 ft. 2843 arboreum
9.9.14 Punakha
10,000 ft.
Tongsa Valley divide
2040 grande, Wt. 20 ft. bush in fruit
13.9.14 Pumthang Valley
10,000 ft.
2088 hodgsonii, Hk. f. 20 ft. bush in fruit
13.9.14 "     10,000 ft. 2089 arboreum, Sm. 10 ft. bush in fruit
22.9.14 "     12,500 ft. 2146 cinnabarinum 6 ft. bush in fruit
22.9.14 "     12,500 ft. 2147 wallichii aff. 8-10 ft. bush in fruit, leaf red below
22.9.14 "     12,500 ft. 2148 lanatum 8-10 ft. bush in fruit strongly veined leaves
22.9.14 "     12,500 ft. 2149 wallichii aff. In fruit under junipers
22.9.14 "     12,500 ft. 2154 cinnabarinum In fruit below spruce
23.9.14 "     13,000 ft. 2217 campanulatum 9 ft. bush in fruit
23.9.14 "     14,000 ft. 2223 elaeagnoides 1 ft. bush in fruit
23.9.14 "     14,000 ft. 2224 thyodocum 2 ft. bush in fruit
23.9.14 "     12,500 ft. 2233 hodgsonii 10-20 ft. bush in fruit
7.10.14 Tongsa Valley
8,000 ft.
2315 griffithianum 10-15 ft. shrub in fruit
25.10.14 Bhutan-Tibet
14,000 ft.
divide (south side)
3479 lepidotum 1 ft. shrub in fruit
25.10.14 "     14,000 ft. 3480 campanulatum, Don 2 ft. shrub growing with 3479 leaves rufous below, but twigs glabrous, seeds blue
25.10.14 "     15,000 ft. 3482 setosum in seed the smallest and reaching the highest elevations of any Rhod.
25.10.14 "     15,000 ft. 3483 nivale 6 in. to 1 ft. high, in fruit
26.10.14 "     13,000 ft. 3484 campanulatum Leaf and twig and fruit woolly, 6 ft. bush in fruit, rare
26.10.14 "     13,500 ft. 3485 anthopogon 1-2 ft. bush in fruit
26.10.14 Timpu Valley
14,000 ft.
3487 anthopogon Fragments of a bush in fruit
26.10.14 Timpu Valley
13,000 ft.
3490 campanulatum 6 ft. bush in fruit, leaf woolly below
26.10.14 "    13,000 ft. 3491 campylocarpum 10 ft. elongated shrub in fruit, entirely glabrous
26.10.14 "    13,000 ft. 3492 wallichii aff. 10 ft. bush, leaf with brown coarse hairs above, scattered black hairs below
26.10.14 "    13,000 ft. 3493 cinnabarinum 10 ft. bush in fruit, leaf oblong-ovate, 2x3/4 in., purple-pink gland dotted above, pitted below
27.10.14 "    14,000 ft. 3498 campanulatum 5 ft. bush on western slopes only, in fruit
30.10.14 "      8,000 ft. 3503 arboreum Leaf silver below, 10 ft. bush in fruit
30.10.14 "    10,500 ft. 3505 thomsonii 10 ft. bush in fruit
30.10.14 "    10,500 ft. *3506 cooperi, Bf. f. 6 ft. bush in fruit only, with golden glands below leaf
30.10.14 "    10,500 ft. 3507 barbatum, smithii (?) Coarse scattered hairs on fruits and young growths
30.10.14 "    13,000 ft. 3527 campanulatum Don Cf. No. 3528 which it resembles but bears better seed
4.11.14 "    13,000 ft. 3528 campanulatum, Don Pure orange under leaf, in fruit
4.11.14 "    13,000 ft. 3540 arboreum 20 ft. bush, reddish-silvery under leaf, in fruit
4.11.14 "    13,000 ft. 3541 triflorum 10 ft. bush in fruit, leaf silvery below, buds pink
7.11.14 Paro Valley
11,000 ft.
3569 lepidotum Small bush in fruit, on sandy peat banks; leaves long- lanceolate and scented
15.11.14 "      9,000 ft. **3588 virgatum aff. Bush 1-3 ft. in fruit, in moss over gravel
15.11.14 "      8,500 ft. 3593 arboreum aff. Leaves wider than usual
18.11.14 Timpu Valley
6,000 ft.
3601 brachysiphon 10 ft. straggly bush in fruit, coppery tinged below leaf
* Flowered in Botanic Garden, Edinburgh, in 1924 as R. cooperi, Balf, j.
** Flowered in April 1920 in Botanic Garden, Edinburgh.
18.11.15 Timpu Valley
6,000 ft.
3615 griffithianum 12 ft. bush bearing large fruits, perhaps 1292
22.4.15 "      5,000 ft. 3786 arboreum 15 ft. bush under oaks, flrs. red with brown spots inside
22.4.15 " 3806 dalhousiae 8 ft. bush, flrs. primrose-yellow
22.4.15 "      6,700 ft. 3807 griffithianum 10 ft. bush, smooth bark, flrs. pure white
22.4.15 "      6,700 ft. 3809 griffithianum Similar to 3807, but bark is not smooth and the flrs. are tinged with red
22.4.15 "      7,000 ft. 3815 virgatum Small bush, flrs. pink
22.4.15 "      6,500 ft. 3816 epapillatum 17 ft. tree, flrs. pale pink with red spots
22.4.15 "      7,000 ft. 3818 smithii 4 ft. shrub, red flrs., hairy petioles
24.4.15 "      7,000 ft. 3819 cinnabarinum 6 ft. bush, long orange flrs.
29.4.15 Paro Valley
10,000 ft.
3830 aff. hodgsonii (?) sp. nov. 20 ft. bush, below Abies forest, flrs. purple, leaf bronzed below
22.4.15 "      9,000 ft. 3831 triflorum 2 ft. straggly bush on limey soil, below pinus excelsa, flrs. yellow
29.4.15 "      9,000 ft. 3833 arboreum 10-15 ft. bush, flrs. red, edged white, leaves smaller, acute, not so silvery
3.5.15 Bhutan-Tibet
14,500 ft. divide
3838 nivale flrs. deep purple, on peat turf, dwarf
4.5.15 Paro Valley
12,000 ft.
3851 wallichii 6 ft. bush, flrs. beautiful pale yellow, leaves light green below, scabrid, polished dark green above
4.5.15 "    10,000 ft. 3855 ... Dwarf shrub in lee of rocks, leaves, small, hairy, flrs. yellow
5.5.15 "    10,500 ft. 3873 cinnabarinum 6 ft. bush under oak forest, flrs. orange to half yellow and pure white
5.5.15 "    12,000 ft. 3874 lanatum aff. 6 ft. bush under birch forest, firs yellow, under leaf densely woolly brown
5.5.15 Paro Valley
11,000 ft
3875 campylocarpum 10 ft. bush in oak forest, firs, yellow with orange tinge in centre of petals
5.5.15 "     10,000 ft. 3876 pendulum 2 ft. bush hanging on mossy rock faces, petals white with red lips
5.15.15 Paro valley (from a temple altar offering) 3879 edgeworthii Flrs. white, scented, leaves hairy, brown below, corrugated above
10.5.15 "     10,000 ft. 3885 papillatum, Bf. f. et Cpr. Bush under spruce forest, flrs. pale cream, frilled edges, blood-red blotch at base of lower petal, fading out to scattered pink spots
15.5.15 Timpu Valley
9,500 ft.
3897 falconeri 20-25 ft. in mixed forest flrs. creamy white, viscid, with dark purple blotch in the throat, leaves 9x4 in., dark green above, rufous beneath
15.5.15 "     13,000 ft. 3903 haemonium, Bf. f. et Cpr. Dwarf shrub on hilltops, flrs. yellow
15.5.15 "     13,000 ft. 3904 wightii 4 ft. bush, yellow flrs.
15.5.15 "     13,000 ft. 3905 fulgens Dwarf bush on peat. flrs. pure red, leaves entirely glabrous
15.5.15 "     13,000 ft. 3906 campanulatum 2 ft. bush, flrs. magenta-purple, leaves fawny, woolly below
21.5.15 Timpu-Punakha
9,200 ft. divide
3911 grande, Wt. 12 ft. bush, flrs. pink, leaf silvery brown below, 8 in. long
21.5.15 "       9,000 ft. 3913 keysii 8 ft. bush, flrs. long, tinged orange to green
27.5.15 Punakha Valley
6,500 ft.
3935 dalhousiae 8 ft. bush in fruit, in steep dry hillside
27.5.15 "       7,000 ft. 3936 brachysiphon, Bf. f. et. Cpr. 8 ft. bush, pink, scented, firs on steep dry hillside
29.5.15 "       9,000 ft. 3937 rhabdotum, Bf. f. et. Cpr. 2 trees of 12 ft., on dry rock faces, flrs. long, cream with crimson lines down them, similar perhaps to 3935
29.5.15 Punakha Valley
8,000 ft.
3939 griffithianum 20 ft. bush in fruit
29.5.15 "       8,000 ft. 3940 grande, Wt. 10 ft. bush, in moist scrub. large leaf and silvery below, growing together with 3939
6.6.15 "       7,000 ft. 3957 maddenii 5 ft. bush on dry hillside, flrs. white, with pink lines and yellow throat scented
6.6.15 Punakha-Tongsa
9,000 ft divide
3959 cooperi, Bf. f. Epiphyte on big mossy trees, small bush, flrs. red with glandular spots
8.6.15 "     10,500 ft. 3968 grande, Wt. 10 ft. bush in mixed scrub, flrs. purple, leaf large, with silvery tomentum below
10.6.15 Tongsa Valley
9,000 ft.
3982 vaccinioides aff. 6 in. shrub at edge of oak forest, flrs. pink, small
15.6.15 Pumthang Valley
10,000 ft.
3987 lanatum Bush 20 ft., with pale pink flrs. and pinky brown wool beneath leaf
18.6.15 "       10,000 ft. 3990 campanulatum aff. A rare bush, 8 ft., in fruit, leaves with white tomentum below, turning red when mature
18.6.15 "       10,000 ft. 3991 thomsonii 12 ft. bush, very common, in fruit
19.6.15 "       12,000 ft. 4003 setosum Dwarf bush, with profuse purple flrs., common in peat meadows
19.6.15 "      12,000 ft. 4009 thyodocum Bf. f. et. Cpr. A 3 ft. bush, with lax habit, flrs. purple
20.6.15 "      12,000 ft. 3998 cinnabarinum aff. 15 ft. bush in spruce forest, with absolutely plain yellow flrs., flrs. not typical
1.7.15 "        9,500 ft. 4083 cooperi, Bf. f. Small 4 ft. bush, epiphytic in mossy trees, flrs. wide open, white inside, pink outside, leaves glandular below and green above
1.7.15 "      10,000 ft. 4084 hodgsonii Large bush in fruit, silvery under leaf
1.7.15 "       9,000 ft. 4086 kendrickii, Nutt. A 20 ft. spare bush, in dried flr. and fruit, leaves long, narrow, and glabrous, with crenulating edge
2.7.15 "      12,000 ft. 4101 fulgens aff. 10 ft. bush in fruit, below Abies
2.7.15 "      13,000 ft. 4102 campanulatum aff. 4 ft. bush, with white flrs.
5.7.15 "      11,000 ft. 4115 argipeplum Bf. f. et. Cpr. 6 ft. bush, remarkable for white lining of hairs below leaf, in fruit and dried flrs.
12.7.15 Pumthang Valley
8,000 ft.
4128 salignum Small 1 ft. shrub, with yellow flrs., on steep cliff faces
14.7.15 "      12,500 ft. 4120 wallichii aff. 8 ft. bush, especially hairy and woolly
23.7.15 "      10,000 ft. 4149 argipeplum Bf. f. et. Cpr. Bush in red fir., with hairy leaves
23.7.15 "        9,000 ft. 4160 kendrickii 25 ft. shrub in fruit, leaf narrow, with holly-like edge
30.7.15 Kerted Valley
12,000 ft.
4246 aff. campanulatum (?) 6 ft. bush by lake, with blue flrs., only seen here
2.8.15 "      13,000 ft. 4285 thyodocum Small 4 ft. bush in fruit
2.8.15 "      14,000 ft. 4286 campanulatum 4 ft. bush among boulders, flrs. pink
15.9.15 Tongsa Valley
9,000 ft.
4804 cinnabarinum 10 ft. bush in fruit, beneath Pinus excelsa forest
20.9.15 "      10,000 ft. 4830 smithii 12 ft. bush in fruit
9.15 Pumthang
9,000 ft.
4978 Cf. 4086
Bush in fruit, growing beneath spruce and alder, leaf edge like holly
9.15 Punakha
9,000 ft
4979 cinnabarinum, cf. Cooperi Small bush, flrs. red
9.15 Tongsa
7,000 ft.
4980 Cf. 3957, maddenii In fruit
9.15 "        8,000 ft. 4981 Cf. 3833, arboreum 12 ft. bush, under oak forest
9.15 "        9,000 ft. 4982 cf. cinnabarinum aff., cf. Cooperi 2 ft. bush, on dry hillsides

Rhododendron Species and Cooper's Numbers

anthopogon, Don 3485.
arboreum, Sm. 1291, 1545, 1575, 2089, 2475, 2760, 2843, 2903, 2924, 3503, 3540, 3541, 3593, 3786, 3833, 4981.
argenteum (see grande)
argipeplum, Bf. f. et Cpr. 4115, 4149.
barbatum, Wall. 3507.
brachysiphon, Bf. f. et Cpr. 3601, 3936.
camelliiflorum, Hk. f. 2648.
campanulatum, Don. 1960, 2217, 2592, 3233, 3234, 3480, 3484, 3490, 3498, 3527, 3528, 3906, 3990, 4102, 4246, 4286.
campylocarpum, Hk. f. 2504, 3491, 3875.
cinnabarinum, Hk. f. 1937, 2146, 2154, 2581, 2922, 3256, 3493, 3819, 3873, 3998, 4804, 4979, 4982.
cooperi, Bf. f. 3506, 3959, 4083, 4979, 4982.
dalhousiae, Hk. f. 3806.
edgeworthii, Hk. f. 2756, 3879.
elaeagnoides, Hk. f. 2223.
epapillatum, Bf. f. et Cpr. 3816.
falconeri, Hk. f. 3897.
fulgens, Hk. f. 3905, 4101.
grande, Wt 2040, 3911, 3940, 3968.
griffithianum, Wt. 2315, 3615, 3807, 3809, 3939.
haemonium, Bf. f. et Cpr. 3903.
hodgsonii, Hk. f. 2088, 2505, 2233, 3830, 4084.
kendrickii, Nutt. 4086, 4160, 4978.
keysii, Nutt. 1456, 3913, 3383.
lanatum, Hk. f. 2148, 3874, 3987.
lepidotum, Wall. 2523, 2552, 3236, 3479, 3569.
maddenii, Hk.f. 1292, 3423, 3957, 4980.
nivale, Hk. f. 3483, 3838.
obovatum, Hk. f. 1805.
papillatum, Bf. f. et Cpr. 3885.
pendulum, Hk. f. 3876.
polyandrum, Hutch. 1454.
rhabdotum, Bf. f. et Cpr. 3937, 3935.
salignum, Hk. f. 4128.
setosum, Don. 2490, 3482, 4003.
smithii, Nutt . 3257, 3818, 4830.
thomsonii, Hk. f. 2928, 3505, 3991.
thyodocum, Bf. f. et Cpr. 2224, 3235, 4009, 4285.
triflorum, Hk. f. 3541, 3831.
vaccinioides, Hk. f. 3982.
virgatum, Hk. f. 1516, 1547, 3064, 3151, 3346, 3588, 3815,
wallichii, Hk. f. 2147, 2149, 2489, 2503, 3238, 3492, 3851, 4120.
wightii, Hk. f. 2590, 3234, 3904.