New Burmo-Chinese Species of Didymocarpus. 
BY 
W. W. SMITH. 
With Plates CIII.-CVII. 
THE descriptions of the following six species of Didymocarpus 
are based on material in the Herbaria of the Royal Gardens at 
Kew and Edinburgh. Iam indebted to the Director of Kew for 
the loan of several sheets, which have been of much service. 
I have not followed Kuntze in including under the generic 
name Roettlera, Vahl both Didymocarpus and Chirita. The 
distinguishing mark between these two genera is the character 
of the stigma which is entire in Didymocarpus and bifid in Chirita 
(Bentham and Hooker, Gen. Plant., vol. 11. p. 995). This character 
is, however, supported by the distinct facies of each in the field 
and toa certain extent a difference in habitat. The Didymocarpt 
are plants of the rock-clefts, while the Chiritae are usually at a 
lower altitude and less restricted in their choice of habitat. The 
difference in facies is one rather difficult to define in words, but in 
areas such as the Eastern Himalayas where both genera are well 
represented, the general aspect of each is so distinct that examina- 
tion of the characters of the stigma is not necessary in determining 
the genus of a specimen in the field. 
Exceptional forms do occur, however, in other areas. Thus 
Didymocarpus Lacei, W.W .Smith, fromthe Gokteik Gorge in Upper 
Burma is a species with the Chirita facies but with the stigma of 
the Didymocarpi. The genus Didymocarpus was recognised by 
Bentham and Hooker as a very polymorphic one and easily 
separable into sections worthy of generic rank. The number 
of species of this and allied genera yet to be obtained from 
S.E. Asia is in all probability so large that it is expedient to 
retain what is undoubtedly a satisfactory division in most in- 
Stances. This is true especially of the Eu-didymocarpi. If 
Chirita is included, the position of Didissandra would also have 
to be considered, for certain species of that genus approach very 
(Notes, R.B.G., Edin., No. XXIV., January 1912.) 
