Evans: Notes on genus Herberta 203 



antheridia occur not only in the axils of the bracts but also in the 

 axils of the bracteoles.* In order to determine whether this phe- 

 nomenon was widespread among the Ptilidioideae, to which 

 group Herberta is usually assigned, he examined species of several 

 other genera. The closely related Mastigophora, however, was the 

 only one in which he was able to observe antheridial bracteoles. 

 In the case of Herberta the bracteoles differ from the bracts in 

 about the same way that the ordinary underleaves differ from the 

 leaves. Both bracts (Text fig. 20; Plate 8, figs. 8, 9) and 

 bracteoles are more or less imbricated and have a broad inflated 

 pocket at the base enclosing a cluster of two or more antheridia. 

 The pocket does not involve the entire width of the basal region 

 but leaves a narrow flattish or revolute strip on each side. In the 

 inflated portion the cells are broader and much paler than ordinary 

 cells, and the thickenings of the walls are more irregular in outline 

 and less strongly developed. The divisions, sinus, and margins 

 are much the same as on ordinary leaves. 



The perichaetial bracts (Plate 8, figs. 10, 11) and bracteoles 

 are essentially alike. They occur in three or four closely crowded 

 series and increase somewhat in size toward the perianth, only 

 the apical portion of which projects beyond them. Those of the 

 innermost series, when viewed from the outer surface, show two 

 rounded ridges in the basal portion, separated by a narrow median 

 groove. A marginal band on each side is flat or slightly concave. 

 The divisions are much the same as on ordinary leaves but the 

 margins are much more toothed, the teeth being irregular and 

 extending higher up, sometimes almost to the apices of the divisions. 

 Occasionally minute and irregular paraphyllia (Plate 8, fig. 12) 

 with marginal papillae are found among the bracts. According 

 to Spruce the bracts closely embrace the perianth but are free 

 from it throughout their entire length; according to Stephani they 

 are coalescent with the perianth up to a considerable height. A 

 longitudinal section through a young sporophyte and surround- 

 ing parts (Text fig. 8) shows that Spruce was essentially correct. 

 Any coalescence which may be present is so slight as to be prac- 

 tically negligible. Between the innermost bracts and bracteole 

 and the leaves below the involucre there is a gradual transition. 



* Untersiichungen iiber Amphigastrial-Antheridien unci iiber den Bau der 

 Androcien der Ptilidioideen. Hedwigia 50: 146-162. / i-jg 1910. 



