ENGELMANN—NORTH AM. SPECIES OF JUNCUS. 429 
The proportion of stamens and sepals, and of anthers and 
filaments, is often very constant, but in some species they 
vary very much, as may be seen in J. scirpoides , the different 
forms of which bear stamens of different length and anthers 
of different size without exhibiting other characters of suffi¬ 
cient specific value. 
In a rare form of J. Poemerianus I find both circles of 
stamens suppressed or rather undeveloped and in a rudiment¬ 
ary state, so that those plants become uni-sexual. Correspond¬ 
ing male plants may perhaps yet be discovered. 
Filaments are always present; in some species they are 
very short, in others elongated, in all dilated at base, and, at 
least in the hexandrous ones, more or less united. Their 
base, which in the young flower adheres to the base of the 
pistil, after fecundation remains attached to the base of the 
sepals. 
The shape of the anthers is of slight importance; they are 
longer or shorter, linear or oblong, in some' species pointed 
or cuspidate, in most others obtuse or emarginate, more or 
less sagittate at base, but these characters show little con¬ 
stancy. 
Pistil. —The pistil exhibits great differences in its form and 
furnishes good and generally constant characters. The ovary 
is obtuse or acute, gradually or abruptly elongated into the 
style; this organ is often very short but in many species it 
has the length of the ovary, or even exceeds it; in a few spe¬ 
cies only it is variable, e. g. in J. scirpoides , which in this as 
in most other organs offers a degree of variability scarcely seen 
in any other species. The stigmas are longer or shorter than 
the ovary with the style, always (except in Juncellus) three 
in number, very slender and more or less twisted; in J. acutus 
they are short and thick, and in J. stygius , as already Lin¬ 
naeus remarks, short and recurved. In just expanding flowers 
the length of the stamens is often equal to that of the ovary 
and style together, so that the stigmas only emerge from 
between the anthers, or they are equal to the ovary alone 
when the whole style with the stigmas protrudes over the 
anthers. 
Capsule. —The capsule is diagnostically one of the most 
important organs in Junci. It varies from globose to ovate, 
obovate, prismatic, pyramidal or subulate, terete or angular, 
retuse, obtuse or acute, mucronate or rostrate; it is shorter 
or longer than the sepals or equal to them; but all these 
characters vary within certain limits, in some species more 
than in others, and ohjy the examination of a large number 
of specimens can decide about their constancy and value in a 
given species. The capsule is always* three-valved (excepting 
again Juncellus ), opening into the cells, the valves bearing 
on their median line the placentae either immediately (parie- 
