428 TRANS. OF THE ACAD. OF SCIENCE. 



the sub-genus Juncellus, I find each circle consisting of two 

 parts only, a curious and rare arrangement in a monocotyl- 

 edonous plant. 



In place of flowers Ave find, in some species with articulate 

 leaves, leafy buds or shoots as the result of retrograde meta- 

 morphosis, or as the morbid product of the oviposition of the 

 Livia Juncorum or some allied insect. They are most com- 

 mon in J. pelocarpus, which, from this peculiarity, has been 

 named viviparzis and abortivus ; in J. pallesce)is,var. fra- 

 ternus, which therefore got the name J. paradoxus, and in J. 

 nodosus genuinus. 



Sepals. — The always persistent sepals furnish important 

 characteristics. The exterior and interior ones are sometimes 

 similar but more frequently dissimilar; the former usually 

 carinate or naviculate, more herbaceous, more strongly ribbed 

 and sharper pointed ; the latter more delicate, with a wider 

 membranaceous margin, flat or slightly concave but not navic- 

 ulate, and more frequently obtuse or only mucronate, but more 

 variable in their outline than the exterior ones. Both sets 

 of sepals are either equal in length or one exceeds the other, 

 but neither their proportion nor the form of the inner sepals 

 ofler perfectly reliable characters in all species ; in some they 

 are more constant, while in others they vary considerably. 

 In examining dried, and even living, specimens, the error of 

 mistaking an involute sepal for an acute one must be avoided, 

 an error into which even careful botanists have sometimes 

 fallen. The nerves of the sepals, which are of such diagnostic 

 importance in Graminem and even Cyperaceai, are of minor 

 value in Junci, as they vory considerably in different forms 

 of the same species. 



Stamens. — E. Meyer had already paid attention to the 

 number of stamens and their proportion, and in many species 

 valuable characters are derived from them, but they alone 

 cannot constitute specific distinction. They are generally 

 persistent, which permits us to examine them in all stages of 

 development of the flower and fruit; only in J. Smithii and 

 in J. Roemerianus the anthers fall away early and the filaments 

 only persist. The number of stamens is normally six, but in 

 many, principally American, species, it is, by suppression of 

 the inner circle, reduced to three ; those three stamens stand, 

 therefore, before the outer sepals and at the angles of the 

 ovary or capsule. We have only two species in which their 

 number regularly varies between three and six, J. Bucklexji 

 and J. caudatus; in them the inner circle of stamens is in- 

 completely present. In many tri-androus species we find 

 occasionally a fourth or fifth stamen, and that often smaller 

 than the rest ; but where both circles are regularly developed 

 I have never seen them unequal in size or shape, which we 

 notice so often in other allied families. 



