3i 
Phytogeny of the Cyperaceae. 
Fig. 7. Part of a transverse section of the culm of Scirpus cyperinus , taken just at the base of 
the nodal region, showing the beginning of division in the cortical bundles to form the annular 
anastomosis, x 75. 
Fig. 8. Part of a transverse section through the middle of a node of an aerial stem of Scirpus 
cyperinus . Most of the fibro- vascular bundles show the amphivasal condition ; a few are collateral, 
while certain ones show intermediate conditions, x 50. 
Fig. 9. Part of a radial longitudinal section through a node of the culm of Scirpus cyperinus , 
showing the annular amphivasal bundles of the nodal complex in cross-section. The base of the 
leaf-sheath appears above at the right. x 40. 
Fig. 10. Part of a radial longitudinal section of a rhizome of Scirpus cyperinus. The endo- 
dermis is just to the right of the centre. On the right is the cortex, showing a leaf-trace on the 
extreme margin. To the left is the outer portion of the central cylinder, with the circular amphi- 
vasal strands of the superficial reticulum appearing in cross-section, x 40. 
Fig. 11. Part of a transverse section through an internode of the culm of Scirpus robtistus . 
A type of the Chlorocyperaceae, with large medullary air-spaces, well-developed palisade layer, and 
numerous stomata, x 75. 
Fig. 12. Part of a transverse section through the culm of Eleocharis palustris, showing extreme 
reduction of the tissues. A few stellate ‘bulkhead ’ cells are shown on the left, x 75. 
Fig. 13. Part of a transverse section of the culm of Dulichium arundinaceum , just above 
a node, showing a section of the leaf-sheath externally, and the two circles of bundles in the stem, 
the inner of which is the proper cauline series, and the outer or cortical series, alternating with large 
air-spaces, x 30. 
Fig. 14. Part of a slightly oblique transverse section through a node of the culm of Dulichium. 
The portion at the right is the lower, showing two series of bundles. At the left the section passes 
into the upper part of the node, where there are three series of bundles : the inner, or cauline ; the 
outer, or leaf-trace ; and the middle, or cortical series of the next higher internode. The central 
part of the figure shows the nodal anastomosis, with part of the nodal diaphragm below, x 20. 
PLATE IT. 
Fig. 15. Part of a transverse section of the rhizome of Scirpus fltiviatilis, showing the peculiar 
sclerotic zone outside the endodermis. x 50. 
Fig. 16. Part of a transverse section of the rhizome of Scirpus americanus . A type of the 
Centrivasae. x 60. 
Fig. 17. Transverse section of the central cylinder of the rhizome of Carex lupulina. A type 
of the Amphivasae. x 20. 
Fig. 18. Part of a transverse section of the central cylinder of the rhizome of Cladium 
mariscoides. Cavernous medulla and cortex, and endodermis hardly distinguishable, x 50. 
Fig. 19. Part of a transverse section of the rhizome of Eleocharis palustris. x 40. 
Fig. 20. Transverse section of the axis of the inflorescence of Eleocharis palustris , showing the 
simple tubular central cylinder which is characteristic of the floral axis proper throughout the 
Cyperaceae. x 25. 
Note. — The nomenclature embodied in this paper is based chiefly upon that found in Gray’s 
Manual, sixth edition, and in the Flora of Britton and Brown, edition of 1896. Upon more 
critical study, and after a comparison with the results of recent investigations in this field, it appears 
that the following corrections are desirable : — 
For Scirpus microcarpus , Presl, read Scirpus rubrotinctus , Fernald. 
For Eleocharis ovata , R. & S., read Eleocharis obtusa, Schultes. 
For Eriophorum gracile, Koch, read Eriophorum tenellum , Nutt. 
For Eriophorum vagina turn, L., read Eriophorum callitrix , Cham. 
On these matters see Rhodora, ii, 1900, p. 20, and vii, 1905, pp. 85-87. Also Proc. Am. Acad. 
Sci., xxxiv, 1899, p. 492. 
The writer is indebted to Mr. M. L. Fernald, of the Gray Herbarium, for these facts. 
