BOTANY. 57 



spo7itanea?n, or that he has seen a living wild specimen ; while v. v. c. means 

 vidi vivani cultam, or that the author has seen a living cultivated specimen. 

 The asterisk prefixed to a name (*L), indicates that there is a good descrip- 

 tion at the reference given to the work ; while the dagger (tL), implies 

 some doubt or uncertainty. The point of admiration (!DC), marks that an 

 authentic specimen has been seen, from the author named ; and the point of 

 interrogation (?) indicates doubts as to the correctness of genus, species, (fee, 

 according as it is placed after the name of the one or other. O, O, <i'. or 

 A, annual; .? , OO, @, or B, biennial ; i|. A, or P. perennial ; h, or Sh., 

 shrub ; ), twining to the left ; (, tAvining to the right ; « , hermaphrodite ; 

 J , male ; ? , female : j — ? . monoecious, or the male and female on one 

 plant; 5 : ?, dioecious, or the male and female on different plants ; 00 or 5*, 

 means indefinite in number. 



Section A. Cryptogamous Plants. 



Class 1. Acotyledones, Juss. Acrogens and Thallogens, Lindl. 



The plants belonging to this class are in some instances composed entirely 

 of cellular tissue ; in other instances, both cells and vessels are present. 

 The vascular tissue in the higher orders consists partly of closed spiral and 

 scalariform vessels. Many of them have no true stem nor leaves. The 

 woody stem, when present, consists of vascular bundles, Avhich increase in 

 an acrogenous manner. The stem of tree-ferns (which illustrates this class) 

 is unbranched, more or less uniformly cylindrical, hollow in the interior, and 

 marked by the scars of the leaves. iStofJiata occur in the epidermis of the 

 higher divisions. Leaves, when present, have frequently no true venation ; at 

 other times the venation is forked. There are no flowers, and no distinct 

 stamens nor pistils. Reproduction takes place in some cases apparently by 

 the union of cells of difierent kinds (antheridia and pistillidia), by means of 

 which germinating bodies called spores are formed. In other cases it is 

 dilEcult to trace this process of fertilization. The spore may be considered as 

 a cellular embryo which has no cotyledons, and germinates from an}»- part of 

 its surface, being heterorhizal. 



Sub-class 1. AmphiganicB, Thallog enes, or Cellular es. 



Acotyledons composed entirely of cellular tissue, having no distinct axis, 

 nor leaves, nor stomata, propagated by means of spores which are often in- 

 closed in asci. 



Order 1. Alg.e, the Sea-weed Family. Cellular plants found both in salt 

 and in fresh water. Fronds composed of variously formed, often elongated 

 cells, which are either simple or branched filaments, continuous or articu- 

 lated, separate or combined in different ways, so as to constitute fronds of 

 different kinds. Growth takes place by the division of cells, or by cellular 



57 



