1916-17.] BOTANICAL SOCIETY OF EDINBURGH 209 



S.E. Yunnan : — Mengtsz. Mountain forests to south-east. 

 7000 ft. Tree 20 f t. ^ Flowers purple-red. Henry. No. 

 10,275. In Herb. Kew et Edin. 



A species with the general characters of the Irroratum 

 series, and probably approaching most nearly to Rh. gym- 

 nantJium, Diels. It has the long narrow leaves of that 

 species, but a glance suffices to distinguish them. Here the 

 upper surface of the leaves is a mat dull olive-green, in RJi. 

 gymnanthum, Diels the upper surface is a bright glossy 

 glaucous green. Then the remarkable development of 

 glandular setae is a feature not seen in Rh. gymiianthum, 

 nor, indeed, in any other of the Irroratum series. These 

 setae form a thick persistent sheath on the petioles and 

 stems and on the ovary are most striking. All the setae 

 are not glandular, some of them have pointed ends, and are 

 much longer than those with glands reaching in length as 

 much as 4 mm. The leaf-surfaces at maturity are con- 

 spicuously red-punctulate, more so indeed (particularly the 

 upper surface) than in some others of the Irroratum series. 

 The glands themselves are frequently persistent, especially 

 on the primary veins, and the flocks of greasy hairs are 

 also often persistent, particularly on or about the midrib 

 and mavkedly towards its base. In the last-mentioned 

 character Rh. fiiengtszense recalls its ally Rh. arampJtyllum, 

 where the flocks remain sometimes as a dense tomentum. 



By its openly campanulate corolla it also differs from Rh. 

 gymnanthum, where the corolla is funnel-shaped, and, in 

 addition to the setose ovary already mentioned, the gland- 

 ular style marks it off" from Rli. gymnanthum, in which 

 both ovary and style are glabrous. 



Diagnostic characters separating Rh. mengtszense from 

 Rh. irroratum are no less conspicuous. These are the 

 longer and narrower leaves, the gland-setose indumentum, 

 the corolla without glands outside and glabrous inside, and 

 the pubescent disk. 



Hemsley and Wilson ^ take this plant with others (Nos. 

 10,301, 10,853, 11,066, 11,067, 11,067b) of Henry's collecting 

 in S.E. Yunnan to be Rh. irroratum, Franch., associating 

 with it also a Tseku specimen No. 4 of Monbeig and 

 Forrest's Nos. 2043, 2058, 4146. Rehder and Wilson 2 refer 

 1 In Kew Bull. (1910), 112. - Plantae Wilsonianae, i (1913), 539. 



