Korthalsella japonica
(Thunb.) Engl. in Engl. & Prantl, Nat. Pflanzenfam. 1: 138. 1897.
Viscum japonicum Thunb. in Trans. Linn. Soc. London 2: 329. 1794. V. opuntia Thunb., Fl. Jap.
64. 1784, nom. superfl.; Hook. f., Fl. Brit. India 5: 226. 1886. Korthalsella opuntia (Thunb.) Merr.
in Bot. Mag. (Tokyo) 30: 68. 1916, nom. illeg.
Yellowish, aerial partial stem-parasites, up to 15 (-20) cm long , much branched; branching
di- or trichotomous, main stem with about 8 - 25 internodes, the unbranched extremities with
about 5 internodes, often densely flabellately branched by the occurrence of collateral branches
arising from the nodes; plants basally cylindrical and flattened at the apex, the following
internodes strongly flattened, narrow spathulate to oblong-spathulate, 10 - 25 mm long, 4 - 8 mm
broad, with a prominent midrib and usually 3 - 5 lateral veins. Leaves rudimentary, encircling the
node, 0.2 - 0.5 mm long, thin, truncate. Floral cushion with or without a few hairs, if present they
are probably modifications of very small bracts, scarcely protruding, reddish. Flowers in a
cluster from the axils with the exception of the lowermost, gradually emerging from the axils, first
few-flowered and later many, up to 8 per cluster, the opposite clusters meet and encircle the
stem. Male flowers: solitary, globose, ca 0.75 mm; anthers united to form a synandrium in the
centre. Female flowers: ca 1.5 x 0.7 mm; ovules not distinct. Fruits subpyriform, usually 1 - 2 mm
long.
Fl. & Fr. March - Aug.
Distrib. India: In arid areas on inner hills in moist deciduous forests between 1000 to 2500 m, in the Himalayan ranges and high hills of Western Ghats in the south, absent in other places. Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh and Tamil Nadu (Nilgiri Hills). This disjunct distribution is probably due to the lack of the required altitudinal range, hosts in the intervening areas, and adds to several such examples of affinities between the Himalayas and Nilgiri Hills of South India.
Habitat & Ecology. In India, it is mostly found in humid forests above 1800 m but extends to savannah vegetations at the specified altitude. It is never recorded in the lowlands of India, though the occurrence is not so frequent. Specificity of hosts might have played a key role in its distribution.
Pakistan, Sri Lanka, Bhutan, Japan, Myanmar, China, Thailand, Vietnam, Malesia, Australia, East Africa, Indian Ocean Islands and Pacific Islands.
Hosts. Various species of Rhododendron are the most favourite hosts for this species, though occasionally it occurs on Eurya japonica, Quercus semicarpifolia and seldom on other hosts. Conifers are generally avoided.
Fl. & Fr. March - Aug.
Distrib. India: In arid areas on inner hills in moist deciduous forests between 1000 to 2500 m, in the Himalayan ranges and high hills of Western Ghats in the south, absent in other places. Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh and Tamil Nadu (Nilgiri Hills). This disjunct distribution is probably due to the lack of the required altitudinal range, hosts in the intervening areas, and adds to several such examples of affinities between the Himalayas and Nilgiri Hills of South India.
Habitat & Ecology. In India, it is mostly found in humid forests above 1800 m but extends to savannah vegetations at the specified altitude. It is never recorded in the lowlands of India, though the occurrence is not so frequent. Specificity of hosts might have played a key role in its distribution.
Pakistan, Sri Lanka, Bhutan, Japan, Myanmar, China, Thailand, Vietnam, Malesia, Australia, East Africa, Indian Ocean Islands and Pacific Islands.
Hosts. Various species of Rhododendron are the most favourite hosts for this species, though occasionally it occurs on Eurya japonica, Quercus semicarpifolia and seldom on other hosts. Conifers are generally avoided.
