In the years from 1950 onwards more than 200 new species of plants were discovered in Nepal. Prior to this the gathering and cataloguing was the prerogative of plant specialists such as Buchanan Hamilton, Wallich, Hooker and Burkill. In the 1920s two Nepalese collectors working for the British Museum amassed new plants for botanical science. Once Nepal opened its frontiers explorers and scientists carried out organised expeditions in the field of botany.

Prior to the 1950s Nepal's knowledge of its plants was limited mainly to local herbalists and medical practitioners (Ayurvedic Vaidhyas, Kabirajs) who collected plants in the wild for medicines. This practice and knowledge was passed down through the generations with little documentation.

In the 1960s a systematic study was prepared based on modern scientific methods by the Department of Medicinal Plants of His Majesty's Government of Nepal, with a herbarium started at the same time. Staff members were sent out for botanical collection and attached also to foreign expeditions engaged in botanical explorations. After this the herbarium had acquired over 60,000 specimens of vascular plants. Staff members were also sent to the famous herbariums of the world, such as Calcutta, Dehra Dun, Kew, Grenoble and Washington D.C. for training. By the 1970s there were 3121 species of Angrosperms, 24 species of Gymnosperms and 308 species of Pteridophytes, with 1,242 genera and 210 families of plants.

For ecology and vegetation purposes Nepal could be divided into four floristic regions i.e. (a) western (b) north-western (c) central, and (d) eastern, and bio- climatically these are broken down into twenty regions from humid tropical climate to the alpine arid regions. But for the purpose of identifying Nepal s flora for the special interest tourist, the following shows the zones from the point of view of altitude i.e. Tropical zone (below 1,000 m), Sub Tropical Zone (1,000 to 2,100 m), Temperate Zone (2,100 to 3,100 m), Sub Alpine Zone (3,100 to 4,100 m), the Alpine Zone (4,100 to 4,500 m), and the Alpine Steppe region.

In the Tropical zone, consisting of the Terai, Siwalik hills and the Dun valleys, with warm humid climate the natural vegetation is dominated by Shorea robusta, plus Dillenca, Terminalia, Adina, Careya, Eugenia and Salmalia to name a few.

In eastern Nepal still in the tropical zone there is Cycas pectinata, Gentum montanum, Calamis sp, Padamus sp, Cyathea spiolusa, and Podocarpus nereifolius.

In the Sub-Tropical zone in eastern and central Nepal there is Schima-Castanopsis, where as in western Nepal Pinusroxbugnii. Dry oak forest of Quercus incana, Q. lantana with certain quantities of Rhododendron arboreum, and Lyonia ovalifolia occur on southern aspects usually below the pines.

The Temperate zone contains evergreen oaks, Rhododendrons and laurels in eastern and central Nepal, while in western Nepal it is the zone of evergreen coniferous forest on the one hand and deciduous mixed forest on the other. In western Nepal quite a few west Himalayan plants like Cedrus deodara, Cupressus, torulosa, Picea smithiana, Abies pindron, Aesculus indicus, and Juglans regia occur frequently. East Himalayan trees like Quercus lamellosa, Daphnephyllum himalayanse, Magnolia campbellii, Talauma hudsonii, do not occur further west of central Nepal. The upper level of the temperate zone usually has a band of Tsuga dumosa and Rhododendron barbatum forest between the temperate broad-leaved forest and the sub-alpine conifer-oak forest. A distinct belt of deciduous forest consisting of Acer, Magnolia and Pentapanax, occurs in the montane zone of eastern Nepal.

In the Sub-Alpine zone coniferous forest of Abies spectabilis is found at the lower levels and Betula-Rhododendron carysanulatum forest at upper levels near the timber line. Many species of Rhododendron occur in eastern Nepal and their number falls as one travels towards central and western Nepal.

The Alpine zone consists of moist scrub vegetation above the timber line of mostly Rhododendron, Juniperus and Berberis. Beyond the alpine scrub meadows, rocks and screes, there are colourful herbs, grasses and sedges, namely Meconopsis, Primula, Gentiana, Croydalis and Saxifraga. Many new species of plants indigenous to Nepal have been discovered in the alpine and sub-alpine zones.

Alpine steppe vegetation lies north of the Dhaulagiri Annapurna massif and the heads of inner valley Himalayas - consisting of grasses and sedges with cushions of Cavagana, Lonicera, Juniperus and Berberis. First of all visit The Godavari Botanical Gardens in Kathmandu, then plan your journey from there.

Tropical Zone - Winter - November to March and Spring - The Terai, Royal Shukla Phanta Wildlife Reserve , Royal Chitwan National Park , Royal Bardiya National Park , Koshi Tappu Wildlife Reserve .

Sub-Tropical Zone - Winter and Spring - November to March - Royal Gardens, Godavari Nagarjun Royal Forests, Phulchoki Hills, Shivapuri Hills, Mahabharat and Chure Range of Hills

Temperate Zone - Spring and Autumn - Pokhara , Central west and eastern Nepal, Langtang National Park .

Sub-Alpine Zone - Spring and Autumn - Makalu-Barun National Park , Sagarmatha National Park , Dolpo, Jumla, Humla, Manang, Jomsom, Upper Mustang, Dhorpatan, Helambu

Alpine Zone - Monsoon - July, August and September - Higher Himalayan Belts, Gosaikunda, Annapurna Region, Everest Region, Upper Dolpo, Upper Makalu- Barun Area.