THE GEXrS DIPLACUS. 153 



Mimiili or Eunani ; nor are there any herbaceous or half- 

 shrubby Diplaci. Diplucus has a completely revolute ver- 

 nation ; the young leaves in all Mimuli are more or less 

 distinctly conduplicate, never revolute. The resinous exu- 

 dation common to all species of Diplacns, and which is most 

 copious in those species which have least j)ubesceuce, is 

 totally absent from Mimulus and EunanuB ; though the 

 latter has that very different thing, a glandular piibescence, 

 and the former displays in many species, a slimy, but not 

 resinous, exudation or pubescence. 



What has misled those authors who have retained these 

 shrubs in Mimulus, has been the strong analogy which they 

 bear, when seen in leaf and Hower, to the Atlantic American 

 and typical Mimulus. They do not at all so nearly resemble 

 the yellow-flowered Mimnlus of Pacific America ; for these 

 species have broad, and for the most part, parallel-veined 

 leaves, and are pale flaccid more or less slimy and musk- 

 scented herbs, so very unlike the typical 2Iimidus that I 

 formerly set them apart as a subgenus Simiolus, and often 

 think they should, along with their South American kindred— 

 M. luieus, Linn., being the type of the whole group— be dis- 

 tinguished as a genus by themselves. But that this general 

 likeness which the Diplacus species bear to 21. ringens— 

 although it misled Mr. Benthara so completely that, in the 

 Sci'ophularinere Indies), he placed them in the type-section of 

 the genus JUmnlus—thnt this is but an analogy, and not an 

 indication of close affinity, is proven by the different ver- 

 nation of Diplacus ; and it was at last acknowledged by Dr. 

 Gray himself -and that without knowledge of the vernation 

 for, in the Supplement to the Synoptical Flora, he says of the 

 various "subgenera" of Mimulus: '' Diplncvs is placed 

 first, as having the best claims to generic distinction." 



Although the genus is, to my mind, one of the clearest 

 far more naturally distinct from 3Iimulus than Pentsiemon 

 from Chclonc or Orthocarpus from CastiUcia, or Sijuihyris 

 from Wulfenia^ihe species are not as well defined ; or at 

 least, not so easily definable in writing. But this difticulty I 



