180 
Anatomie. 
Holm, Th., Anemonella thalictroides (L.) Spach; an anatomical 
study. (Am. Journ. of Sc. IV. 24. p. 243—248. figures 1—5. Sept. 1907.) 
This plant was described as an Anemone by Linnaeus, and 
accepted as such by Bentham and Hooker; according to Richard 
it became a Thalictrum , until it was raised to generic rank as 
Syndesmon by Hoffmannsegg, though only as a name; some years 
later Spach described it as monotypic genus Anemonella. 
In several respects the plant is quite remarkable and possesses 
some features in common with Anemone (the involucre and the 
white petaloid calyx), some others with Thalictrum (the costate 
achenium with one pendulous ovule), and finally with Isopyrum 
(the habitus). The ovule of Anemonella has two integuments, and in 
this respect it agrees with Thalictrum, but not with Anemone. Very 
characteristic of the plant are the tuberous roots, which contain 
large deposits of starch. The increase in thickness depends upon 
the formation of pericambial cork, a secondary cortex, a number of 
secondary, collateral mestome-strands, and a broad, central pith. 
The stem has no collenchyma, and no endodermis, but a stereomatic 
pericycle, which surrounds a single circular band ot collateral 
mestome-strands. This same structure was, also, found in the very 
long petioles. The leaves are bifacial, and the larger veins possess 
a collenchymatic Support, besides that they are surrounded by 
typical parenchyma sheaths. The axis, thus, shows a monostelic 
structure, while Thalictrum has an astelic. Theo Holm. 
Holm, Th., Morphological and anatomical studies of the 
vegetative organs of Rhexia. (Bot. Gazette XLIV. p. 22—33. 
plates I—II. July. 1907.) 
In Rhexia Virginica L. the vegetative propagation takes place 
by means of root shoots, and, although the species is a perennial, 
no other rhizome becomes developed than the one formed by the 
basal stem internodes with their roots, besides the root from which 
it has developed. The seedling is very small with epigeic cotyledons, 
and the primary root does not grow out into any considerable length. 
In some of the lateral roots an increase in thickness takes place to 
such an extent that a portion of the roots becomes swollen, and it 
is from this swollen part that a root shoot will develop, though not 
until the next spring. The seedling dies down to the ground during 
the autumn, and the swollen roots are, thus, the only parts of the 
young plant which remain alive. These roots winter over, and in 
the following spring a young shoot develops, with scale-like, opposite 
leaves, and with several pairs of secondary roots from the nodes. 
One or more of the secondary roots soon commence to increase in 
thickness, developing fusiform tubers, which then give rise to new 
shoots, and this same course of vegetative propagation becomes 
repeated year after year. Old tuberous roots may develop several 
strong shoots, each of which is provided with a number of secondary 
roots. In regard to the anatomical structure of the swollen roots, 
the increase in thickness is caused by the rapid activity of the 
pericambium from which cork and a secondary cortex becomes 
developed, besides that secondary, collateral mestome-strands appear 
in a circular band around the primordial Stele; no ducts, and no 
stereias were observed in these roots, but druids of calcium oxalate 
were quite frequent. 
