б DR. ОТТО STAPF ON HALLIERACANTHA, 
HazrrzrkRACANTHA, а New Genus of Acanthacem. By Dr. Отто Star, F.L.S., 
Principal Assistant, Herbarium, Royal Botanic Gardens, Kew. 
[ Read 7th February, 1907.] 
THE genus Ptyssiglottis was established by T. Anderson? on Fihytiglossa 
radicosa, a plant described by Nees* from specimens collected by Champion 
in Ceylon. Rhytiglossa comprised originally a few South African species. 
Subsequently the genus was considerably enlarged by the addition of other, 
mainly American, species, growing thereby rather heterogeneous, and at 
present its species are distributed over several genera. There is no doubt 
that T. Anderson was perfectly justified in separating the Ceylon species from 
Rhytiglossa, in whichever sense that genus may be taken. His description of 
Ptyssiglottis is, so far as it goes, unobjectionable. Unfortunately, however, 
he adopted Miquel’s* view that the Ceylon Rhytiglossa radicosa of Nees was 
identical with the Mostellularia sarmentosa of Zollinger *, an identification 
that is difficult to understand, as the description of Rostellularia sarmentosa, 
and still more the comparison of the specimens, do not suggest any close 
relationship. Miquel’s statement did not remain unchallenged. Bentham ° 
suggested that the Zostellularia sarmentosa of Java might be specifically 
distinct from Ptyssiglottis radicosa, and С. B. Clarke” more emphatically 
stated that the former * does not belong here,” viz. to Ptyssiglottis. Notwith- 
standing those eritical remarks Ptyssiglottis was generally enumerated as a 
monotypic genus inhabiting Ceylon and Java, until, in 1896, Hallier #17 
published two new species of Ptyssiglottis from Borneo and several more? in 
the following year, also from Borneo. In referring those Borneo species to 
Ptyssiglottis, he relied on a rather incomplete specimen of Ptyssiglottis radicosa 
in the Buitenzorg Herbarium and Anderson’s description of that plant. 
Subsequently he saw the specimens of Ptyssiglottis radicosa in the Kew 
Herbarium. Referring to them he said? they were not sufficient to contirm 
the placing of his new species from Borneo in Ptyssiglottis. 
When some years ago I was working out Haviland’s and Hose’s Acanthacex 
from Sarawak, several species which were evidently congeneric with Hallier’s 
Ptyssiglottis attracted my attention, but also convinced me of their generic 
distinctness from the Ptyssiglottis of Ceylon. This induced me to examine 
* In Thwaites, Enum. Pl. Zeyl. (1860) p. 235. 
* In De Candolle's Prodr. vol. xi. (1847) p. 344. 
? Fl. Ind. Bat. ii. (1856) p. 825. 
+ Ех Nees in De Candolle, 7. с. p. 370. 
* In Benth. & Hook. f. Gen. Pl. vol. ii. (1876) p. 1118. 
° In Hook. f. Fl. Brit. Ind. vol. iv. (1885) р. 544. 
7 In Ann. Jard. Buitenz. vol. xiii. (1896) pp. 289-298, t. 23. figs. 2, a-c. 
* In Nov. Act. Nat. Сит. lxx. (1898) pp. 212-228, tabb. 9-16. 
° In Bull. Herb. Boiss. vol. vi. (1898) p. 622. 
