160 Introductory FieW of the 



hide to the laurustinus (F. 7'inus) of the south of Europe, 

 which displays its white flowers even amid the whiter snow. 

 One of the British species, too, is known rather by a variety 

 than by its common mode of growth : the Guelder rose {V, 

 CXpulus) bears its flowers in cymes, like the elder tree ; but 

 the flowers are larger, and those in the outer part of the cyme 

 are larger than those in the centre : the variety usually culti- 

 vated, and called the snow-ball tree, has the whole cyme com- 

 posed of the larger flowers (which are barren), and crowded 

 so close, as to form a round ball. We should hesitate whether 

 to prefer this variety when in blossom ; and certainly, when 

 the blossoms fall, it is inferior to the common Guelder rose, 

 since it wants the bright red berry, which is as handsome to 

 the eye, as it is nauseous to the taste. There is another na- 

 tive species, called the wayfaring tree (Fiburnum Xantana). 

 The leaves of both assume a deep red colour in the au- 

 tumn; and it has been observed that this change is very 

 common in the British species of such genera as are chiefly 

 American. 



The sumach, or poison oak (jRhus), is a large foreign genus 

 of this order, powerfully poisonous. From the .Rhus vernix, 

 or varnish tree, is obtained the fine varnish of the Japanese ; 

 and another, well known in England by the name of copal var- 

 nish, is produced by the JRhus copallina. The smooth sumach 

 (jRhus glabra) is common in our shrubberies : the stem and 

 branches are clothed with a thick and soft scarlet down ; the 

 leaves are pztmate ; the leaflets large, serrated, and elegantly 

 graduated, from the length of four inches at the base, to two 

 inches, or less, at the apex ; in the autumn they assume a fine 

 crimson. Several of the species are so poisonous as to be 

 very dangerous neighbours ; and it is asserted that a swarm 

 of bees, alighting upon a branch of the varnish tree, was 

 instantly destroyed by its effluvia only. 



Of the fourth order there are but two genera; of the first 

 of which, Britain possesses one species ; the grass of Parnassus. 

 The fifth order also is a small one, of which there are but 

 three genera in the British Flora : but among them is one 

 species worth whole genera of common plants. It is a slight 

 little plant, about two feet high, with lanceolate leaves, and 

 bearing a panicle of very pretty, blue, veiny flowers. To this 

 plant we are indebted for that most exquisite of luxuries, 

 linen, and for an article perhaps yet more valuable, paper. 

 It is the Z/lnum usitatissimum, the common flax. An oil is 

 • pressed from the seeds (called line or tin seed), which is used 

 by artists; and the seeds themselves are applied to many 

 medicinal purposes ; but the plant is chiefly cultivated for the 



