Cordaianthus shuleri is the only species based upon 
fructifications of Cordaites (or Mesoawylon) for which both 
staminate and ovulate strobili are known. Indeed, there 
are paleobotanists who would insist on giving distinct 
specific names to the two sexes; and this in spite of the 
similarity in size, construction, and histology of the two 
types of strobill. 
Cordaianthus shuleri belongs to a species of Mesoxylon 
(4, p. 129). 
In 1918, D.H.Scott reported the occurrence of spe- 
cial axillary shoots associated with Mesovylon multirame 
which has a more or less flattened stele, a bilaterally 
symmetrical construction and a distichous arrangement 
of branches bearing spirally arranged bracts. In the fol- 
lowing year, he described (18) these fertile shoots in detail 
and referred to them the seeds known as Mitrospermum 
compressum A. Arber (1) which, however, (despite a re- 
markable frequence) were not found in organic attach- 
ment. Scott was of the opinion that the dozen seeds lying 
near a single shoot were probably originally attached to it. 
A nearly transverse section of the axis of Mesowylon 
multirame measured 6.5 mm. X1.5mm. and showed a de- 
tached branch lying proximal to the main axis. In this 
branch the stele was round and had a large pith. Scott 
described each branch as receiving a small stele from the 
main shoot, but this stele rapidly expanded and became 
medullated. The bracts had a single mesarch vascular 
bundle. The wood of the fertile shoot consisted of spiral 
and sealariform tracheids, and conforms with the inner 
zone of wood of the ordinary Mesowylon stem. This struc- 
ture is in reality a Cordaianthus. 
Scott described this inflorescence, belonging without 
reasonable doubt to Mesowylon multirame, from the mid- 
dle Carboniferous of Britain. The specimen he figured 
consisted of naked shoots borne in the axils of leaves. A 
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