Nepal is situated at longitude 80°15’-88°10’ E

and latitude 26°30’-30°10’ N. The breadth from west to east distanted 880 km

and from north to south about 177 km. The northernmost is the so called ’world roof

and the south part is lower than 100m above the sea level. The zonation characterized by the climate and geophysiognomy is very distinct

the south part below alt. 1000m is tropic in nature

the middle lowland from alt.1000 to 2200 m is subtropic

from alt. 2200 to 4500m is mountain temperate zone

from alt. 4500 to 5200 m is mountain frigid

and above 5200 m is the high mountain tundra

similar to the arctic climate.The seeded plants of Nepalese flora consisted of 1451 genera and about 5000 species

and additionally about 500 species of ferns. Among them

72 families belong to tropical elements

but most of them are represented by minor genera and species (see table 1). Another 54 families belong to subtropical representatives

and most of the herbal families are consisted of greater number of genera and species

ie. Scrophulariaceae (38 g: 165 s)

Ranumculaceae (19:142)

Saxifragaceae (12:129). and Gentianaceae (12:98); contrarily

the woody families are consisted of lesser representatives

as seen in Magnoliaceae (4:11)

Theaceae (5:10)

Fagaceae (3:16)

Styracaceae (2:3)

Betulaceae (2:4)

Corylaceae (2:4) and Hamatnelidaceae (1:1). The cosmopolitan families are usually consisted of numeral genera and species

they are Leguminosae (80:289)

Compositae (114:288)

Orchidaceae (89:208)

Labiatae (48:148)

Gramineae (111:355)

Cyperaceae (19:176) and Rosaceae (29:175).The gymnospermous flora of Nepal is as poor as those of Xichang (Tibet) and Indian floras

totally 8 families 15 genera and 27 species were recorded

among them

the Pinaceae possesed 6 genera and 10 species

and only one species was represented in Podocarpaceae and Taxaceae respectively

and no Taxodiaceous representatives were found. As compard with the Yunnan flora where there are 80 species of gymnosperm belong to 25 genera and 10 families

it is much poorer than the letter

Vertically

from the lowland to the gracial line

there existed distinct plant zonations. The dipterocarp (Shorea robusta) and figs (Ficus regiosa and F. lacor

etc.) usually lift up to 1200m. The evergreen subtropieal trees

such as Quercus

Michelia

Machilus

Schima

Symplocos and Ilex dominated from alt. 1100 to 3600m; simultanously

the asiatic common fern Dicranopteris linearis

usually accompanied with the evergreen trees and never exceeed the upper limit

but the deciduous broad-leaved trees such as Acer and others would be found at alt. 3000m under the spruce forest. The lowland pine

Pinus roxburghii

togather with hemlock

Tsuga dumosa

distributed side by side with the evergreen broad-leaved trees. Spruce forest (Picea smithiana)

the dominated needle forest

exceeded the evergreen broad-leaved forests distributed from alt. 2500 to 3500 m. Above the needle forest is the high mountain steppe

dominated by Saxifraga

Androsace

Primula

Pedicularis

Iris and Carex

etc.The species of Rhododendron are widely distributed from lowland to Alpine

R. arboreum

an evergreen rose-bay

ranged from alt. 1600 to 2500 m

above it from 2400 to 3000 m

it was replaced by shrubby evergreen R. lepidotum

and uppermost were replacd by deciduous Rhododendron.The Nepalese flora is closely related to the Cathaysian flora

within 1451 genera of Nepalese flora there are only 107 genera were not found in Yunnan and Xichang

among them 46 genera are scattered in northwest and north-east China or in south China

actually only 61 genera were disappeared in Chinese flora. So far as we know

there are 14 indigenous genera are recorded from Napal

they are Cedrus of Pinaeceae

Thomsonia of Araceae

Paroxygraphis of Ranunculaceae

Arcyospermum

Chrysobraya

Ermaniopsis and Glaribraya of Cruciferae

Indopiptadenia of Papilionaceae

Gamblea of Araliaceae

Caesulia and Gatamixix of Compositae

Treutlera of Asclepiadaceae

Eckemukerzea of Polygonaceae

and Sympagia of Acanihaceae.Among the 5000 species of Nepalese flora

there are 2379 species were found from Yunnan

and 1774 species from Xichang

totally more. than 60% belongs to the Chinese Flora. Moreover

those of the tropical elements found from Nepalese flora are rather closely related with Yunnan than those of Xichang

and contra rily

the subtropical ones are rather closely affined to Xichang than those of Yunnan. It seems to be

that the Nepalese flora is as young as those of Xichang

and is more younger than those of Yunnan.Geologically

Himalaya was lifted up during Tertiary

the age of Nepalese flora would not be older than 40 million years

and the numericals cited above tell us that except 61 genera

nearly all of the genera of Nepalese flora are coexisted at China

and togather with the poverty of the gymnospermous flora of Nepal

made us to conclude that the Nepalese flora is the descendants of the Cathaysian flora.The Nepalese flora is inevitably interfused with other neighbour floras

except 14 endemic genera

the remain 47 genera are coexisted at India

Southeast Asia and Arabis

especially on the western arid region

the xerophylous representatives

such as Urginea and Dipcadi of Liliaceae

Tiliacorea of Menispermaceae

Chrosophora of Euphobiaceae

Christolea and Ermania of Cruciferae

Helinus of Rhamnaceae

Argrolobium and Paracalyx of Leguminosae

Notonia of Compositae

Caralluma of Asclepiadaceae

Maharanga of Boraginaceae

and Ecbolium of Acanthaceae are coexisted at North-Africa and the region of Mediterranean Sea; another genera

such as stelis of Orchidaceae

Gonolobus of Asclepiadaceae and Anredera of Ficoidaceae are connected with tropical American flora; and Diphylleia of Berberidaceae. Desidera of Cruciferae

Legonsia of Campanulaceae

Dectylorhiza of Orchidaceae are distributed disjunctively to Arctic and Alaska