194 Evans: Notes on genus Herberta 



other respects, the shoots appear almost radial in structure. The 

 inflorescence is invariably dioicous. The androecium is at first 

 terminal on a secondary stem or one of its branches but soon pro- 

 liferates, and the male shoot eventually shows a series of short 

 intercalary androecia separated by equally short sections bearing 

 normal leaves. The archegonia are likewise terminal on sec- 

 ondary stems. When fertilization takes place the growth of the 

 female stem is usually brought to an end ; when fertilization does 

 not take place one or more subfloral innovations may be pro- 

 duced. The involucre is composed of crowded bracts and bracte- 

 oles, which are essentially alike and not very different from the 

 leaves, while the perianth is deeply laciniate at the mouth and free 

 or nearly so from the bracts. The calyptra and the sporophyte 

 conform to the usual jungermanniaceous type. 



The rhizome of Herberta was apparently overlooked by the 

 older writers. Spruce,* however, calls attention to it and to the 

 fact that it may bear rhizoids, while Stephani mentions its small 

 diameter and copious branching. It tends, in fact, to be con- 

 siderably more slender than the secondary stems, although both 

 vary in size. In H. juniperma, for example, an average rhizome 

 measures only 0.35 X 0.25 mm. in cross section, while a stem 

 measures 0.5 X 0.35. The features of the rhizome are not easily 

 made out in material where the secondary stems are well developed. 

 The leaves are more or less disintegrated with age and it is dif- 

 ficult to demonstrate the relationship between the branches and 

 the leaves. In most cases the leaves and underleaves are minute 

 and widely separated. The leaves are practically transverse in 

 their insertion and it would be difficult to distinguish them from 

 the underleaves, if the'rhizome did not show a slight dorsiventral 

 flattening, the underleaves being of course situated on one of the 

 flattened sides. Both leaves and underleaves are distinctly bifid. 

 The rhizoids grow out normally from the basal cells of the under- 

 leaves, although they often occur on the leaves as well, but the 

 rhizome itself is usually free from them. The branches are all 

 intercalary and many of them spring from the axils of the under- 

 leaves. This position, however, is not constant; occasional 

 branches tend to be lateral and do not show a definite relationship 



* Trans. Bot. Soc. Edinburgh 15: 340. 1885. 



