AND ANATOMY OF THE STEM OF LYCOPODIUM. 23 
of the plants where the stem is plagiotropic a cluster of roots may be observed, and then 
above this no further trace of them is evident outside. Besides growing toa greater length 
than Z. Selago, L. serratum is marked by, comparatively speaking, large leaves, which 
vary, however, in breadth from 1to5mm. The vascular cylinder may attain considerably 
greater proportions in ZL. serratum (Pl. 4. fig. 22), and the general configuration 
of xylem and phloem is more broken; this, as in the case of L. alpinum, leads to the 
formation of isolated phloem-regions and three phloem-islands are shown, but, in these, 
sieve-tubes are not well developed. Cavities do not occur at the base of the leaves as in 
L. Selago. Inthesmaller plants, which had been formed from bulbils, two or three roots 
were found in the cortex, and in old plants as many as nine were observed in some 
sections. These roots do not grow very far, but from the central cylinder new roots are 
continually being produced every few centimetres, and the old ones gradually die out. 
The triarch stage (fig. 23) is taken from the stem of a young plant derived from a bulbil. 
Of other species which were very cursorily examined, L. volubile, Frost, shows, as 
Mr. Boodle has already indicated, a definite banded structure. A specimen named 
L. uliginosum is very similar to L. annotinum, and shows the same development of cortex, 
but the cavities in the leaf-base are wanting. L. tetragonum, Hook, is similar to 
-L. Selago ; internal roots are found, and the xylem is cruciate and shows the same broad 
periphery. JL. reflexum, Lam., resembles L. serratum both in the star-like arrangement 
of xylem and the isolation of portions of phloems and also in the presence of internal 
roots. 
LYCOPODIUM SQUARROSUM, Frost. 
In the abstract of a paper communicated to the British Association by the writer in 
1897, which was subsequently published as a note in the ‘ Annals of Botany’ (vol. xii. 
1898, p. 558), it was pointed out that there are a number of Lycopods, mostly tropical 
epiphytes, which differ in several anatomical points from species found in this country and 
in Europe generally. Of these L. squarrosum was taken as a type, and included with it 
were L. Dalhousieanum, Phlegmaria, and nummularifolium. Externally these plants are 
characterised by radial symmetry and orthotropie growth. Several features in their 
internal structure are distinctive : the xylem is not arranged in separate narrow strips, 
but owing to cross-connections the general configuration is more irregular, and by these 
cross-connections the phloem in the centre is cut off into isolated portions or islands ; the 
differentiation of the protoxylem does not proceed uniformly from the outer elements to 
those of the centre as is the case in the clavatum type, and the outer portions of some of 
the xylems, consisting of protoxylems only or together with a few metaxylem-elements, 
are isolated from the main mass; the sieve-tubes are grouped together in a cluster; also 
there is little or no mechanical tissue formed in the cortex. Most of these plants have 
leaves which are large for Lycopods ; they show well-marked leaf-bases, but the leaves are 
whorled in several cases, or very nearly so. 
In L. squarrosum the leaves are not regular, and alternating pseudo-whorls of six or 
seven leaves occur ; the branches very gradually decrease in size, and dichotomy is the 
SECOND SERIES.—BOTANY, VOL. VII. F 
