MONOCHLAMTDE^. 651 



are especially liable to be attacked by insects, which thus produces excre- 

 scencfs, coni'monly called galls. The more important of which are the Nut 

 Galls of commerce, and the large Mecca or Bussorah Galls of Pereira; which 

 are called also Dead-sea apples, mad apples, and apples ofSudom. The latter 

 are jirodiiced by Cynips itisana on the Quei cus inft ctoria. The former are also 

 produced on the branches of the same tree by the Cynips gallcB tinclorice. They 

 are extensively employed in tanning, for making ink, and for other purposes 

 iii the arts, &c. The' best come from the Levant. Two kinds are especially 

 known, namely hluf and white. The dark coloured imperforate galls are the 

 most valuable. The acorns of some species of Quercus, as Q. Ballota, Q. 

 esculenta, and Q. Hindsii are edible. 



Natiu-al Order 230. Myricace^e. — The Gale or Bog- Myrtle 

 Order. — Shrubby plants, with alternate, simple, resinous-dotted 

 leaves. Flowers unisexual, amentaceous. Male flowers achla- 

 mydeous ; stomens definite. Female flowers -with, a 1 -celled ovary, 

 ha\'ing 1 erect ovule ; fruit drupaceous ; seed solitary, erect ; 

 embryo without albumen ; radicle superior. 



Distribution, Sfc. — Natives of the temperate parts of Europe 

 and North America, and of the tropical regions of South America, 

 India, and the Cape of Good Hope. Examples: — Myrica, 

 Comptonia. There are 3 genera, and about 20 species. 



Properties and Uses. — The plants of this order are chiefly 

 remarkable for aromatic and astringent properties. 



Myrica — M. cerifera, the Waxberry, Candleberry, or Wax Myrtle. The 

 bark of the root is extensively used in the United" States as a stimulant as- 

 tringent in diarrhoea and dysentery. The fruits when boiled yield the knidof 

 wax known as Myrtle Wax. Other species of Myrica yield a somewhat similar 

 waxy sub-tance. The fruit of M. sapida is eaten in Nt- paul. 



Corup/or.ia asplertifolia. Sweet Fern, is employed in the United States as 

 an astringent and tonic in diarrhoea. 



Natural Order 231. Casuarinace^e. — The Beefwood Order. 

 — Trees, with pendulous, jointed, striated branches, without 

 evident leaves. Flowers in bracteated spikes or heads, unisexual. 

 Male flowers with 2 sepals and 2 alternating bracts, the former 

 being united at their points ; and 1 stamen with a 2-celled anther. 

 Female flowers in dense spikes or heads, naked, but each having 

 2 bracts ; ovary 1 -celled, with 1 — 2 ascending ovules, and 2 

 styles. Fruit winged, indehiscent, collected together into a cone- 

 shaped body. Seed without albumen ; radicle superior. 



Distribution, ^c. — They are principally natives of Australia. 

 They are called Beef-wood trees from the colour of their timber 

 resembling raw beef. In general appearance they resemble the 

 branched Equiseta. Examples : — There is 1 genera, and about 

 32 species. 



Properties and Uses. — The species of Casuarijia yield very 

 hard and heavy timber, and the bark of some is said to be tonic 

 and astringent. 



Casuarina. — Several species produce valuable timber, which is chiefly used 

 in this country for inlaving and marqueterie. The wood is known under the 

 names of Beel'-wood, Botany Bay Oak, Forest Oak, He-Oak, She-Oak, &c. 



Natural Order 232. Betulace^. — The Birch Order. — Trees 

 or shrubs. Leaves simple, alternate, with deciduous stipules. 



