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BALANIA HARLANDII (Hook. F.) V. T., OF THE
HONG KONG REGION AND ITS RELATIVES,
by
WILLIAM ALbert SetchELL.
THE UNIVERSITY OF CALIFORNIA, BERKELEY, CALIFORNIA, U.S.A.
The parasitic element in any flora, local or general, is of the greatest interest not only to taxonomists but also to plant geographers. The features of importance in such an element are the proportional flora constituted by it and the particular character of the parasitic assemblage as to diversity both of parasitism and taxonomic, or perhaps better, phyletic relationship, One other matter comes into definite prominence regarding such an element, and that is, the nature and variety of the hosts upon which the parasites depend, largely or wholly, for their support and nourishment,
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Of the somewhat over 1,000 species of flowering plants indigenous (or native) to the Island of Hong Kong, distributed through about 575 genera, there are known only 7 species of parasitic flowering plants dis- tributed through nearly as many genera and representing 5 natural families, The green hemiparasites, Cassytha, Loranthus (“Mistletoe "), and Viscum (with 2 species, also "Mistletoe ") are stem parasites, while Henslowia, presumably, is a root parasite. Aeginetia (a form of Broom-rape ") and Balanophora (or Balania) Harlandii are both non-green (or colour- less") holoparasites on roots or underground stems. The families of hemiparasites (green) represented are Lauracea (Cassytha), Loranthacea (Loranthus and Viscum), and Santalaceæ (Henslowia), while the holopara- sites (non-green) belong to Orobanchacea (Aeginetia) and Balanophoraceæ (Balania). The species are all subtropical to temperate south eastern Asian, with distribution (with the possible exception of the last mentioned) ad- mittedly extending well beyond the borders of Hong Kong proper.
Our particular interest is with Balania Harlandii, thus far considered to be restricted to (or endemic to) Hong Kong Island.
Endemics to a flora are always of the greatest importance and suggest various possibilities for their occurrence. Bentham (1861) estimated that there were about 1,000 species indigenous (or native) to Hong Kong, distributed through about 550 genera. Of these species Bentham considered 159 species to be endemic. Later discoveries increased the number of indigenous species as well as reduced the number to be considered endemic. Tutcher (1905) in his review of the Hong Kong flora, estimates that not more than 59 of the endemic species of Bentham's list remain on the endemic list, which, however, he considers as increased to 100 among approximately 1,000 indigenous species as included up to 1905. especially in view of the discussion later on in this that some of the Hong Kong species are not found Hupeh Province, about 600 miles to the north.
Of further interest, paper, Tutcher states elsewhere nearer than
It was in 1855 that Dr. Joseph Dalton Hooker presented, at several meetings (February 6, February 20, and June 19) of the Linnean Society of London, a series of papers :-- On the structure and affinities of the
The Hong Kong Naturalist.
The Hong Kong Naturalist Supplement
PRINTED BY S.C.M. POST,
MILLIMETER,
Plate 1.
No. 1-
72