238 NORTH AMERICAN SPECIES OF JUNCUS. 
according to characters taken from their organs of vegetation, their stems and leaves, and also their 
inflorescence, more than from the differences found in their flowers or fruits. In these most essen- 
tial parts all the species show a remarkable uniformity, which will only permit us to make use of 
them to characterize minor divisions, and for specific diagnosis. Desvaux (Journ. Bot., Vol. L, 
Paris, 1808) had already separated our Juncus repens, on account of a peculiarity in the dehiscence 
of the capsule, and some alpine species, because of their long-tailed seeds, as two distinct genera, 
Cephaloxys and Marsippospermum. But we know now that other species of far different alliance 
form a transition from the ordinary loculicidal to the septifragal dehiscence, that species of all forms 
and sections, and otherwise very dissimilar, have tailed seeds, and that others exhibit all the 
transitions from the tailed and loosely tunicated to the merely pointed and closely coated seed. 
From the following it will appear that these genera cannot stand even as sections. 
Vegetative Organs. — The different forms of the root-stocks, and of the stems and leaves of these 
plants, are so well known that I need not here dwell upon them; by their differences the principal 
types of Junci are best characterized, i. e. those that produce no leaves or leaves equal to the stem itself, 
those that have channelled or flattened leaves, and those that bear knotted leaves. But I must say 
that we have forms that seem to bridge over these apparently well-marked distinctions, and which 
again prove that Nature knows nothing of our systematic subtleties, and that our systems are only 
an imperfect aid for our limited comprehension. To give an example —no section of Juncus seemed 
to be better characterized and more natural than that of the true Juncit with naked stems and so- 
called lateral inflorescence. To this section we are bound to refer J. Drwnmondi and J. Hallii, 
while J. biglumis, which can scarcely be separated from them, is, in all our systematic works, far 
removed from them. Again, J. Vaseyi comes so close to J. Hallii that we should hesitate whether 
to class it with this or with the flat-leaved J. tenuis, if J. Greenti did not unite it more directly with 
the latter. The form of leaves is not quite constant. While those of the articulate Junci are 
usually described as terete or compressed-terete, the observations of our southern botanists 
prove that in some species, at least, soil and moisture have a most important influence on [426] 
them, as they also have on the development of the inflorescence ; the overgrown forms of 
. scirpoides, as I understand that species, have large, laterally compressed, gladiate leaves, while in 
the forms grown on drier and poorer soil the leaves become almost or entirely terete. On the other 
hand, the peculiar tribe of articulate Junci of the Pacific slope, which I have called Znsifoli¢ trom 
their characteristic sword-shaped leaves, exhibits, in alpine situations, such narrow leaves that they 
might inadvertently be mistaken for terete ones. 
Inflorescence. — The inflorescence offers us important but, to a surprisingly great extent, variable 
characters. All Junci have, as is well known, a terminal inflorescence, even where it is seemingly 
lateral. In the Californian sub-genus Juncellus, and in a few South American and antarctic species 
which form the subgenus Rostkovia (gen. Rostkovia, Hook. f., Rostkovia, Desv., and Marsippospermum, 
Desy., in part), a single flower terminates the stem or scape; but all the true Junci have a more or 
_ cetpeund inflorescence of single flowers or of flowers crowded into larger or smaller heads. 
In the inflorescence we observe numerous bracts, usually of a membranaceous texture; the 
_ uppermost bracts bear in their axils the flowers, which are always lateral, though in the species with 
single flowers they appear terminal. In these the lower of the two highest bracts, which are always 
found at the base of the flower, and which were therefore termed “ calyx” by Rostkovius, bears the 
flower in its axil, the upper one remaining sterile ; but the trace of an axillary product, an abortive 
flower or a leaf-bud, ought occasionally to be found, as is regularly the case in J. pelocarpus. In the 
single-flowered forms of this species the uppermost bract usually bears an abortive bud, or this bud 
grows out into a leafy branch, or it becomes a second flower ; and then a third bract is formed, often 
1 Steudel, in his “‘ Plante Glumacee,” 1855, enumerates 196 species, many of them, however, undoubtedly nominal ones. 
