The prevailing colour of the primulas is purple, but white, yellow, blue, and pink are also found. The _P. denticulata_ has purple to bright sapphire blue flowers, and great stretches of country are almost blue with the lovely heads of this primrose. Miles of country can be seen literally covered with _P. obtusifolia,_ which has purple flowers and a strong metallic smell. _P. Kingii_ is a lovely plant with flowers of such a dark claret colour that they are almost black. And perhaps the most striking primula is _P. Elwesiana,_ with large solitary deflexed purple flowers. Poppies also are a feature of the Sikkim vegetation. Near the huts the people cultivate a majestic species near _Menconopsis simplicifolia,_ but it grows in dense clusters 2 or 3 feet high. The flowers vary in diameter from 5 to 7 inches, and are an intensely vivid blue on opening, though they change before fading into purple. _M. simplicifolia_ itself is also found at altitudes from 12,000 to 15,000 feet--a clear light blue species of special beauty, growing as a single flower on a single stem, and now to be seen at both Edinburgh and Kew. Another beautiful poppy is the _M. nepalensis,_ which grows in the central dampest regions of Sikkim at elevations of 10,000 to 11,000 feet and resembles a miniature hollyhock, the flowers being of a pale golden or sulphur-yellow, 2 or 3 inches in diameter and several on a stalk. As Tangu is approached the valley expands into broad grassy flats, and here at about 13,000 feet the vegetation rapidly diminishes in stature and abundance, and the change in species is very great. Larch, maple, cherry, and spiraea disappear, leaving willows, juniper, stunted birch, silver fir, mountain ash berberries, currant, honeysuckle, azalea, and many rhododendrons. The turfy ground is covered with gentians, potentillas, geraniums, and purple and yellow meconopsis, delphiniums, orchids, saxifrage, campanulas, ranunculus, anemones, primulas (including the magnificent _Primula Sikkimensis),_ and three or four species of ferns. The country being now so much more open, the valley bottom and the mountain-sides glow with purples and yellows of various shades. Not even here, nor indeed anywhere in the Himalaya, do we see that mass and glow of colour we find in California, where wide sheets of meadow-land are ablaze with the purple of the lupins and the gold of the Californian poppy. But for the number of varieties of plants these upper valleys of the Teesta River can scarcely be excelled. As we ascend the mountain-sides above Tangu we find them covered with plants of numerous different kinds, and even at about 14,000 feet Hooker gathered over two hundred plants. But now we are nearing the limit of plant life. At 17,000 feet the vegetation has ceased to be alpine and has become arctic, and the plants nearest the snow-line are minute primulas, saxifrages, gentians, grasses, sedges, some tufted wormwood, and a dwarf rhododendron, the most alpine of wooded plants.