BOTANY. 



581 



a position, one of the edges being for the most part | 

 urned to the sky. 



The form, size, texture, &c. of leaves, furnish many 

 pecific distinctions. Some are named from their 

 escmblance to parts of animal bodies. Others from 

 heir resembling instruments of war, of music, or of 

 ,vell known machines. Others again are named from 

 geometrical figures, or from the heavenly bodies. 

 They have also names to signify to what part of the 

 plant they are attached ; as whether radical, spring- 

 ing directly from the root ; caulinar, growing on the 

 stem; rameum, borne on the branches; (ii'tilary, pro- 

 ceeding from the angle between the stem and a 

 branch : the same term is used in describing flowers, 

 peduncles, or stipules arising from the same place. 

 Leaves are also said to be jloral when placed near 

 the flower, and seminal if they are the first which 

 spring from the seed. 



The terms which most commonly occur in descrip- 

 tive botany are as follow : 



Cordate*, a heart-shaped leaf or leaflet, fig. a, as 

 exemplified in the birthwort and many other plants. 



Rchifi'rm or kidney-shaped, as in ground ivy, fig. b. 

 This term is also frequently applied to seeds. 



Linguifurm, that is tongue-shaped. This descrip- 

 tion of leaf is frequently seen among what are called 

 succulent plants, as in the families of aloes and mes- 

 embryanthemums. It is " linear and fleshy, blunt 

 at the end, convex beneath, and having usually a 

 cartilaginous border," fig. c. 



Ellivtkal, a leaf like an oval, only more elongated, 



fig. k. It often happens in leaves of some of the 

 preceding forms, that the broadest part is most dis- 

 tant from the petiole ; in which case they are said to 

 be obovale, obcordate, c., that is, inversely heart, or 

 egg-shaped. 



Sagittate, arrow-head shaped leaf. This occurs 

 frequently in the arum family, and many other kinds 

 of plants, fig. /. 



Hastate, are such leaves as are shaped like the 

 head of a halbert or battle-axe. This differs but 

 little from the auriculate leaf, fig. d. 



Lanceolate, an oblong leaf which tapers to each 

 end, this is exemplified in the common ribwort, or 

 ribbed leaved plantain, fig. n. 



Ensiform, or sword-shaped leaves, are such a 

 those of the iris, fig. o. 



Auriculate, ear-shaped, or rather having append- 

 ages like ears, or lobes at the base, fig. d. 



Pa/mated, a hand-shaped leaf; example, the com- 

 mon passion-flower, fig. f. 



Digitate, a fingered leaf. This is distinguished from 

 the palmated leaf, in the leaflets representing fingers, 

 being all attached to the point of the petiole or foot- 

 stalk ; whereas the other has a broad space like a 

 palm of a hand, whence the divisions proceed ; the 

 digitate leaf is exemplified in those of the horse- 

 chestnut, fig. g. 



Acinaciform, are leaves resembling' the Persian 

 cimiter : one-edge being convex and sharp, the other 

 nearly straight and thick. Example, mesembryanthc- 

 mum acinaclforme, fig. p. 



Peltate, a target-shaped leaf ; in such the footstalk 

 instead of being inserted into the margin of the leaf, 

 is fixed at or near the centre of the under surface. 

 The ivy-leaved geranium and nasturtium, or Indian 

 cress is a familiar example, fig. q. 



Pedate, that is like a foot of a bird ; a leaf divided 

 into several slender divisions, fig. h. 



Ovate, an egg-shaped leaf, in which the base is 

 somewhat broader than the point, fig. i. 



Oval, an oval-shaped leaf; in which both ends are 

 equal, fig. j. 



Li/ratc, leaves shaped like the musical instrument, 

 the lyre. It is somewhat like a pinnatifd leaf, oniy 

 the terminal segment is very large and rounded, 

 fig. r. 



Dttlalmform, a hatchet-shaped leaf. This very 

 peculiarly formed leaf only occurs among the mesem- 

 bryanthemums. It is thick and Bnccuent ; narrow 

 where it is fixed to the stem, but spread out und 

 rounded at the point like the edge of an axe, fig. s . 



