30 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. X, NO. 2. 



ennial and stoloniferous specimens have been recorded of species that are otherwise typically 

 annual." 



The next large group (2) comprises such species as are typically perennial, and the first of 

 these, C. asarifolia Bong., possesses a horizontally creeping and quite fleshy rhizome, the apex 

 of which bears a number of large leaves with axillary inflorescences. The primary root has van- 

 ished and is replaced by many filiform secondary ones, which proceed from the very short 

 internodes of the rhizome. A like but much more slender rhizome is developed in C. parvifolia 

 Moc, a species that is very characteristic by its alternate stem leaves and by the presence of 

 bulblets in the axils of these. The bulblets resemble very much those of Dentaria iulbifera, 

 Saxifraga cernua, etc. (PL 1, fig. 1.) We now pass to section E, in which the rhizome is 

 vertical and very short, but in which the primary root sometimes attains an enormous develop- 

 ment. To here belong ('. megarrhiza Parry. < '. Virginica L, and their allies. Of these the 

 former is the most remarkable of the genus. The very small seedling (PI. 1, tig. 2) has the 

 cotyledons raised above ground by a short but very distinct hypocotyl (H in rig. 2); the primary 

 root (R) is long and very slender with a few ramifications, densely covered with root hairs. At 

 this stage two leaves, succeeding the cotyledons, are already visible, and the plant is now ready 

 to meet the first winter. The first sign of change in the equipment of this little plant is the 

 loss of the cotyledons; thereupon follows a gradual wrinkling of the hypocotyl, by which the 

 apical bud becomes pulled down beneath the surface of the ground, and the root continues its 

 growth vertically and to a very considerable depth. In the following spring the leaves develop 

 and form soon a small rosette, while the hypocotyl and the basal portion of the root has com- 

 menced to increase in thickness; lateral, slender roots become also developed. (PI- 1. fig- 3.) 

 How soon the flowering begins we do not know, but it is very likely that it takes the plant three 

 or four years before it produces flowers. 



In fully matured specimens the leafy rosette is very large, the hypocotyl still visible as a cylin- 

 dric, thick, and prominently wrinkled body above a long, very fleshy, and thick root, the primary; 

 the lateral roots persist also and increase quite considerably in thickness, but not to such an extent 

 as the main root (PI. 1, fig. 4). If we lay a longitudinal section through the rosette and the 

 hypocotyl, we notice at once a number of small, young inflorescences and leaves ready to push 

 out during next spring. These inflorescences are stalked and erect, and the young flowers are 

 covered by the (fore) leaves. The hypocotyl persists during the whole life of the plant, and 

 constitutes a portion of the wrinkled crown above the root. Characteristic of ('. megarrhiza 

 and arctica is, thus, the continuous growth in length and thickness of the primary root, besides 

 the overwintering of the leaves and inflorescences. 



It is now interesting to study the morphological structure of C. Virginica L.. which no 

 doubt is a near ally of C. megarrhiza; biologically, however, they are very distinct. Let us 

 state at once that C. Virginica does agree with < '. megarrhiza as far as concerns the monopodial 

 shoot and the persisting primary root, though not the entire root. The development of the plant 

 is as follows: 



As already described by GrONOVIXJS,* " Monocotyledonum instar protrudit unicuni foliolum," 

 and so is the only sign of the seedling above ground a single leaf with a small blade borne on a 

 long, filiform petiole (PI. '2, figs. 10 and 12). This leaf is borne upon a small tuberous body 

 underground, which terminates into a long, filiform root (R in fig. 10) with a few ramifications 

 and densely clothed with hairs. An anatomical study of the tuberous body shows at once that 

 this is also a part of the root, and no hypocotyl is thus developed. The base of the petiole 

 closely surrounds a minute leaf (!,' in fig. 11). which sometimes develops during the first season 

 (/' in fig. 13). and this leaf resembles the proper leaves of the full-grown plant. During the first 

 season the base of the root increases rapidly in thickness, while the slender portion dies off and 

 no trace of this is to be found in the following spring. The development of leaves continues at 

 the same time as the root grows in thickness, forming a more or less globular body with many 



"The author: On the vitality of some annual plants. (Am. Journ. of Sci., vol. 42, 1891, p. 304. 

 b Flora Virginica, Pare. I, 1743, p. 25. 



