1 57 
Rhizome of Matonia pectinata. 
NOTES ON 
THE RHIZOME OF MATONIA PECTINATA , R.Br. 
By Grace Wigglesworth. 
[With Plate III.] 
N examining the rhizome of Matonia pectinata, of which some 
preserved material was kindly sent to the Owens College by 
Mr. A. G. Tansley, I found the internal structure differed in some 
respects from that described by Mr. A. C. Seward, 1 and sufficiently, 
I think, to warrant a short description of the main points of differ¬ 
ence. It should be stated at the outget that Mr. Tansley’s 
material of Matonia pectinata was collected on Mount Ophir (Johore), 
while that examined by Mr. Seward came from Matang (Borneo). 
A transverse section of the rhizome of Mr. Tansley’s material, 
taken between two leaves, shows three concentric steles, separated 
from each other by several layers of parenchymatous cells forming 
part of the ground-tissue. The innermost stele encloses a central 
mass of similar parenchymatous cells, and is consequently dis¬ 
tinctly siphonostelic, and not protostelic like the axial strand of 
Mr. Seward’s Matonia. 1 he outermost stele is narrower on the 
dorsal side, and the inner margin is crenulated on the ventral side. 
The middle stele has only two or three depressions on the inner 
margin of the ventral side, while the innermost stele has none or is 
only slightly depressed where the protoxylem group occurs. 
The structure of the central stele is similar to that of the 
other two steles except that it has but one distinct protoxylem 
group instead of several. The protoxylem group lies on the inner 
side, and is ventral in position. The stele has a ring of wood 
vessels mixed with wood parenchyma, surrounded inside and 
outside by several layers of phloem-cells. The phloem is 
surrounded by a layer of parenchymatous cells (pericycle) and 
outside this is an endodermal layer of cells which often contain 
starch. 
About half-an-inch in front of the leaf-insertion the stele is 
open, and U-shaped, so that the central mass of ground tissue is 
continuous with that lying without the central stele. At this point 
(see fig. 1) the middle stele is flattened dorsally and bent slightly 
inwards while the outermost stele remains annular. A little nearer 
the leaf the free ends of the open central siphonostele become 
united with the dorsal part of the middle stele (fig. 2), enclosing 
J A C. Seward. Structure and affinities of Matonia pectinata , 
Pliil. Trans. 1899. 
