166 TRANSACTIONS OF THE [Sess. lxxxi 



styluin), blotch and no spots (Rh. agastuin, Rh. erithnum, 

 Rh. tnengtszense, Rh. spanotrichum), spots and no blotch 

 {Rli. adenostemonum, Rh. irroratwrn, Rh. lukiangense, Rh. 

 j)ogonostyhiin). In Rh. araiophyllum a basal postei^ior 

 large blotch has a beautiful rich dark crimson tint. There 

 are no data through which to correlate some diagnostic 

 characters of clothing of the corolla to which I will now 

 refer, characters which doubtless have a relation to pro- 

 tection in the flower or to attraction in connection with 

 pollination. Rh. irroratum is exceptional in having red 

 glands distributed on the outside of the corolla, and they 

 are present also in Rli. pogonostyhi'm in addition to basal 

 hairs. These are red clavate glands with short stalks, and 

 are mostly seen upon the midrib of the petaline segments and 

 often conspicuously on the back of the lobes. Occasionally 

 they are absent from one or other of the petaline segments, 

 present in the unfolding, but they seem in some cases to fall 

 off as the corolla expands. These glands offer a readily 

 observed mark of distinction within the series, and are in 

 particular useful for separating Rh. irroratum from its 

 nearest ally Rh. adenostemoiium, which bears glands upon 

 the stamina) filaments and not upon the corolla. As a 

 consequence perhaps of this glandular state in these two 

 species, I find their flowers are much more insect-eaten than 

 those in other species. R/i. pogonoHtyluin is an exception 

 also, for the corolla outside is puberulous at the base. Then 

 the inside of the corolhx tube in the series shows two states. 

 In less than one-half of the species {RJi. adenostemonuvi, 

 Rh. agastum, Rh. anthosphaerum, Rh. hylothreptunt, Rh. 

 irroratum, Rh. pogonodyUim) it has a greater or less cover- 

 ing of hairs; in the rest {Rh,. araiophyllwni, Rli. ceraceimi, 

 Rh. eritimum, Rh. gymnanthum, Rh. lukiangense, Rh. 

 mengtszenfie, Rh. .spanotrichum, Rh. tanafityluni) the inside 

 of the tube is glabrous. I suspect there is some corr-elation 

 between these hairs and the red blotch which is always 

 gland-secreting, but have no observations to record. 



i>iplostemony gives to most of the species of tlie Irroratum 

 section 10 stamens. In Rh,. eritimu7n and Rh. hylothreptum, 

 which have 7 petals, there are 14 stamens. Fluctuations from 

 10-12 stamens are found in Rh. agafitum and Rh. antho- 

 sphaerum. Althougli 7 petals occur in Rh. agastwni I have 



