The Lindsaya-Type. 
H5 
one another at an acute angle, approaching to a right angle, which 
is of course directed away from the stem-axis (Fig. 44). “ The 
protoxylem groups are distinct and endarch ; one occurs at the end 
of each arm of the xylem, and sometimes a third is also present at 
its apex. The arms of the xylem-strand are sometimes prolonged 
past the two lateral protoxylems, curving inwards towards the plane 
of symmetry of the petiole so as to torm two small hooks. These 
Jv/>- 
Fig. 44. Odouloloma repens. T. S. of petiolar strand. After Gwynne- 
Vaughan. 
hooks are included in the phloem of the bundle, which is perfectly 
continuous all round the xylem-strand ” (Gwynne-Vaughan, ’03). 
The leaf-trace leaves the stele by the breaking of the dorsal arch of 
xylem which covers the internal phloem, and the passing off of 
tracheids, together with surrounding tissue, from one side of the 
arch, which soon re-closes. The internal phloem of the stele is 
therefore continuous with that of the trace, and the whole structure 
is essentially what would result if the nodal pocket of phloem in 
Gleichenia were continued down through the internode to join that 
of the node below. Owing to the somewhat different shape of the 
leaf-trace the concavity is much less marked, and the ground tissue 
surrounded by endodermis is not carried down so far into the stele 
as is the case in Gleichenia flabellata, but in some cases there is a 
short endodermal pocket extending into the internal phloem below 
the node (Fig. 43 C). 
The Lind say a-type of stele is found in all the species which 
have been examined of Davallia 'sOdontolonia and 
(Synopsis Filicum) except Davallia ( Stenoloina) aculeata (see 
Gwynne-Vaughan, ’03). This last named species, which has been 
put in a separate genus Lindsayopsis by Christ, and Davallia 
pinnata , which has been separated as Wibelia by Christ, show a 
further modification of the Lindsaya- type. 
