Included here are the Himalayas which in biogeographic terms can be divided into the western and eastern Himalayas. The western zone includes the area westward of the Kali Gandaki River Gorge (the world’s deepest valley) in Central Nepal which acts as a biogeographic barrier between the Eastern and Western Himalayan. Also included are the southern slopes and offspurs of the Western Himalayas, the valleys of the rivers Gilgat, Kabul, Kunar, Kurram and Swat, and with mountains like Everest, Dhaulagiri and Makalu, this zone has the tallest peaks on Earth. The eastern Himalayas includes eastern Nepal, Darjeeling, Sikkim, Bhutan, a large part of the Assam Himalayas and the extreme southeastern part of Tibet.

Eastern Himalayan Alpine Scrub and Meadow

Situated between the tree line at about 4000m and the snow line at about 5500m, this habitat complex supports one of the richest floras in the world with some 7000 species. The scrub vegetation is dominated by many colourful rhododendron species often forming distinct assemblages of endemic or near endemic species. In eastern Nepal these include Rhododendron campanulatum, R. campylocarpum, R. thomsonii, R. wallichi and R. wightii. Further east in Bhutan these give way to R. aeruginosum, R. baileyi, R. bhutanense, R. fragariiflorum, R. pogonophylum, R. pumila and R. succothii, while still further east the main species are R. calciphila, R. chryseum, R. crebriflorum, R. riparium, R. saluenseum and R. sanguineum (Ericaceae). However, even the rhododendrons are often less conspicuous than the bright yellow flower stalks of the endemic Nobile rhubard Rheum nobile (Polygonaceae). Other endemics associated with the alpine scrub include Aconitum gammiei (Ranunculaceae), Berberis angulosa, B. erythroclada (Berberidaceae), Cicerbita macrantha (Asteraceae), Codonopsis thalictrifolia (Campanulaceae), Corydalis juncea (Fumariaceae), Geranium refractum (Geraniaceae), Geum sikkense (Rosaceae), Hedysarum campylocarpon (Fabaceae), Lonicera cyanocarpa var. porphyrantha (Caprifoliaceae), Meconopsis simplicifolia, M. sinuate (Papaveraceae), Primula oblique and P. reticulata (Primulaceae. The alpine meadows also support hundreds of herbaceous species often producing a riot of colour in springtime. Some of the endemics found here include Astragalus floridus (Fabaceae) and Ranunculus adoxifolius (Ranunculaceae), but most of the endemics within this zone are more likely to be found on the steeper alpine slopes. These include Adonis nepalensis (Ranunculaceae), Astragalus floridus, A. stipulatus (Fabaceae), Cortiella hookeri (Apiaceae), Delphinium viscosum (Ranunculaceae), Gentiana depressa, G. prolata (Gentianaceae), Geranium nakaoanum (Geraniaceae), Hedysarum sikkimense (Fabaceae), Herminium macrophyllum (Orchidaceae), Lamium tuberosum (Lamiaceae), Lloydia flavonutans (Liliaceae), Primula wigramiana, Primula wollastonii (Primulaceae), Rhododendron glaucophyllum, R. nivale (Ericaceae), Roscoea capitata (Zingeraceae), Salix daltoniana (Salicaceae), Swertia hookeri, S. multicaulis (Gentianaceae) and Tanacetum atkinsonii (Asteraceae), while riverside slopes provide habitat for the endemic Omphalogramma elwissiana (Primulaceae) and Primula sikkimensis (Primulaceae).

Eastern Himalayan Scree Slopes

Surprisingly, this often highly unstable habitat also provides habitat for many endemic species including Arenaria edgworthiana (Caryophyllaceae), Chlorophytum nepalense (Liliaceae), Gentiana urnata (Gentianaceae), Pycnoplinthopsis bhutanica (Brassiaceae), Saxifraga engleriana (Saxifragaceae), Soroseris pumila (Asteraceae), Tanacetum gossypinum (Asteraceae) and Veronica lanuginose (Scrophulariaceae).

Eastern Himalayan Rocks, Rocks Crevices and Ledges

Like in many other mountain ranges, these open rocky habitats provide refuge for many alpine species and often providing ideal conditions for endemic species to develop. In the case of the Eastern Himalayas these include Begonia josephii (Begoniaceae), Codonopsis dicentrifolia (Campanulaceae), Cremanthodium nepalense (Asteraceae), Primula aureata, P. caveana, P. deuteronana, P. gambeliana (Primulaceae), Spathoglottis ixioides (Orchidaceae) and Saxifraga roylei (Saxifragaceae).

Western Himalayan Alpine Scrub and Meadows

These alpine habitat complexes, which occur between 3000-5000 m, can be broadly divided into western and northwestern types. In the former the forest alpine transitions are marked by Krummholz type vegetation of Rhododendron campanulatum, R. barbatum, species of Salix and the endemic Syringa emodi (Oleaceae). This gives way with increasing altitude to colourful alpine scrub composed of dwarf rhododendrons, Cotoneaster microphyllus, Hippophae rhamnoides, Juniper commnis and J. wallichiana. Similar transitions and scrub communities occur in the more northwestern areas.  These scrublands provide habitat for a variety of endemic species including Draba radicans (Brassicaceae), Geranium himalayense (Geraniaceae), Heracleum lallii (Apiaceae), Rubus foliolosus (Rosaceae)and Saussurea roylei (Asteraceae.  In addition, the now widespread Impatiens glandulifera (Himalayan balsam), which is naturalized throughout much of Europe, was once possibly nearly endemic to these alpine scrub communities. At higher altitudes or interspersed among the scrub communities are rich alpine meadows supporting diverse communities of Anaphalis, Anemone, Aster, Cynanthus, Delphinium, Gentiana, Jurinea, Meconopsis, Mertensia, Morina, Pedicularis, Polygonum, Primula, Saussurea, and a high proportion of these, especially in the families Fumariaceae, Primulaceae, Saxifragaceae and Scrophulariaceae are endemic. Examples include Androsace primuloides (Primulaceae), Aster indamellus (Asteraceae), Astragalus himalayanus (near endemic) (Fabaceae), Caragana brevifolia (Fabaceae), Delphinium cashmerianum (near endemic) D. himalaya, D. kamaonense, (Ranunculaceae), Lavatera kashmiriana (Malvaceae), Megacarpaea polyandra (Brassicaceae), Nepeta leucophylla (Lamiaceae), Pedicularis klotzschii (Orobanchaceae), Primula poluninii (Primulaceae), Rheum moorcroftianum (Polygonaceae) and Roylea cinerea (Lamiaceae), although some of these are mainly confined to the more steeper slopes. At very high altitudes, close to the upper limit of plant life, the vegeation is reduced to a few scattered bushes of Rhododendron anthopogon and Berberis spp and the occasional cushions of Cassiope fastigiata. The herbaceous species include Bergenia stracheyi, with its fleshy leaves that turn red in autumn, Ephedra gerardiana, the curious woolly Saussurea gossypiphana, and Paraquilegia anemoides. However, most species tend to peter out before 5000 m, although the near endemic Christolea himalayensis (Brassicaceae) has been recorded at 6300m on Mount Kamet, which is the highest altitude recorded for a flowering plant in the Western Himalayas.

Western Himalayan Rocky Slopes and Ledges

These often exposed, harsh habitats provide niches for a variety of alpine species including a number of endemic species. Among the rough rocky or stony slopes these include Aster tapete, Clematis phlebantha, Gentiana stipitata, Hedysarum cashemirianum, H. kumaonese, Incarvillea younghusbandii, Lilium oxypetalum, Meconopsis latifolia, Onosma bracteayum, Oxytropis cashemiriana, O. mollis, Primula minutissima, Rosa webbiana, Saxifraga poluniniana and Viola kunawarensis. The endemic species, which seem to be mainly confined to rocky ledges, include Primula reidii and P. sharmae (Primulaceae).

Western Himalayan Scree Slopes

Despite their lack of stability these dynamic habitats are home to a number of alpine species including the endemic scree specialists Cremanthodium nanum and C. purpureifolium (Asteraceae).

Western Himalayan Riparian Communities

Along streams and watercourses species of Aletris, Caltha, Pedicularis, Polygonum, Potentilla and Ranunculus are likely to be seen. Endemic species that rely on these wetter areas include Hedysarum microcalyx (Fabaceae) and Oxytropis williamsii (Fabaceae).

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