188 5 A 11 



Ar'bor. A tree ; a perennial plant, which rises to a considerable height,, 

 having a woody stem. Most trees spring from seeds having two co- 

 tyledons ; they are therefore called dicotyledonous plants. The stems 

 of such plants are said to be exogenous, that is, growing externally, 

 new layers of wood being every year formed under the "bark around 

 the outside of the old wood. Palm trees are monocotyledonous 

 plants; their stems are called endogenous, that is, growing internal- 

 ly, and pressing upon the outer coats, which become hard and com- 

 pact. The ancient botanists divided plants into trees and herbs ; 

 but this distinction is too vague to form the basis of classification. 



Arbusti'vus, (from arbuslum, a shrub.) An ancient class of plants con- 

 taining shrubs, as the myrtle, mock-orange, &c. 



Arcuate, (from arcus, a bow.) Bent like a bow. 



Arcnarius. Growing in sand. 



Argcnt'cus. Silver coloured. 



Ar'id. Dry. 



A'ril, (arillus.') The external coat or covering of seeds which, dry- 

 ing, falls off spontaneously. 



Arts' tale, (from area, to be dried.) Awned, ending in a bristle. 



Aro'idcs. So called from arum, and forming a natural family of 

 plants. 



Arms, (arma.} Offensive weapons. Plants are said to be armed, when 

 they are furnished with prickles, thorns, &c. 



Aromab'ic. Sweet scented. 



Ar' row-form. Shaped like an arrow head, the hind lobes acute. 



Articulated. Jointed, as in the culm or stem of the grasses 



Arundina'ceous, (from arundo, a reed.) Resembling reeds. 



Arvcnsis. Growing in cultivated fields. 



Ascending. Rising from the ground obliquely. 



Asperifo'lius. Rough leaved. 



Attcn'uatcd. Gradually diminished or tapering. 



Auric'ulate. Having appendages resembling ears. 



Awl-form. Sharp at the point, and curved to one side. 



Awn. A short stiff bristle. 



Ax'il. The angle between a leaf and stem on the upper side. 



Ax'illary. Growing out of the axils : leaves are said to be axillary 

 when they proceed from the angle formed by the stem and branch 



B. 



Bac'ca. A berry. It is a pulpy pericarp, enclosing seeds without 

 capsules. In the raspberry of a seed. 



Bacdf'erous. Bearing berries. 



Ban'ncr. The upper petal in a papilionaceous flower. 



Barb. A straight process armed with teeth pointing backwards. 



Barba'tus. Bearded. 



tiark. The covering of vegetables, consisting of several parts, as cu- 

 ticle, cellular integument" &c; The bark consists of as many layers 

 as the tree on which it grows has years: a new layer being formed 

 from the cambium every year, the newest layer of bark is called 

 liber. 



Bar'reu. Producing no fruit ; containing stamens only. 



