77
6
WILLIAM ALBERT SETCHELL,
described under different names should really be referred to it. In such case, the idea of its narrow endemism to Hong Kong or even to the Hong Kong general area, must be given up. An examination of the various related species seems fairly definitely to substantiate this latter suggestion,
Ph. van Tieghem investigated thoroughly the green and pale stem and root parasites and published many papers concerning them. In 1896, he divided the old genus Balanophora (to which he restricted the family Balanophoracea) into three genera, according to the structure of the androecium (or staminal column). Balanophora Harlandii Hook. f. became in Van Tieghem's arrangement not the type of, but a member of, a new genus, Balania, V.T., characterized by an androecium of three stamens. horizontal and sessile on the lobes of the perianth, and with their longer diameters forming the three sides of an approximately equilateral triangle.
In 1907, Van Tieghem more fully discussed the Balanophoracea, created two additional genera, Bivolva, V.T., and Balaniella, V.T., and added to Balania three species, B. Henryi (Hemsley), V.T., B. japonica, V.T., and B. ceracea, V.T., the first and third from central China and the second extending from the Liukiu Islands through Shikoku to central southern Nippon in Japan. The geographical segregation of this group of Balania species in China and Japan was noted by Van Tieghem as of special interest, since they form a homogeneous group of dioecious species, related most closely to the group of five species which he placed under his segregate genus Bivolva, V.T. (1906), which, in turn, ranges from the eastern Himalayan region through western China to central China, where the area of dis- tribution of Bivolva, V.T. overlaps the area of distribution of the species of Balania, V.T. In fact, the two genera, Balania and Bivolva, differ only in leaf (or bract? or volva?) splitting, all characters of flower and inflorescence being essentially identical. Two questions come before the investigator at this point: first; are the genera Balania and Bivolva sufficiently distinct from one another to be kept separate? and second; are the various species attributed to each genus to be maintained in whole, or in part?
In regard to the use of the names Balania and Bivolvu, there is a question of nomenclature. Van Tieghem, in 1896 (p. 297), very definitely separates Balanophora involucrata Hook. f. from the rest of the Balanophora species and definitely designates it as the type of a new genus which he christens Balania. He does definitely coin the binomial Balania involucrata, although later, in 1907, when he designates the same species as the type of his genus Bivolva, he does not use the binomial Balania involucrata or refer to his previous disposition of the species. We find, therefore, that the same species is the type of two genera, retained as distinct by Van Tieghem in 1907. Again, in 1896, Van Tieghem does not create the binomial Balania Harlandii, although he leaves the strong impression that he refers it to his genus Balania, and in 1907 (p. 201) he states that it has been Balunia Harlandii (Hook. f.), V.T. since 1896 and that the genus Balania, V.T. has for its type the Balania Harlandii (Hook. f.), V.T.
It seems clear that the genus Bivolva has no legal status and if Balania Harlandii is to be separated, generically, from Balania involucrata,
:
The Hong Kong Naturalist Supplement
No. 1.
PRINTED BY S.C.M POST.
Plate 3.
The Hong Kong Naturalist.
78
Page 60Page 61
No comments yet.
Private notes are available after approval.