HENDERSON'S HANDBOOK OF PLANTS. 



277 



APO 



ceeds from injured or diseased tissues, 

 and is with difficulty arrested when once 

 set up, and, if so, is the certain forerun- 

 ner of fatal canker. In some cases, as in 

 the Tragacanth Plant, the gum is organ- 

 ized, and is derived apparently from the 

 medullary rays. In Conifers a flow of 

 resin is often attended with the same 

 fatal results as gumming in Plums and 

 other allied plants. In this case it seems 

 to arise generally from root confinement 

 and a consequent check of circulation. 

 Apothecia. The shields of Lichens ; firm, 

 horny disks arising from a thallus, etc., 

 containing spores. 



Apothecium. The organ of fructification 

 peculiar to Lichens, which contains their 

 sporules, and is frequently cup-shaped. 

 Appendages. Leaves and all their modifica- 

 tions are appendages of the axis. Hairs, 

 prickles, etc., are appendages of the part 

 which bears them. 



Appendant. Hanging, approaching pendu- 

 lous. 

 Appendiculate, Appendiculated. Furnished 



with appendages. 

 Appense. Being hung up, as a hat upon a 



pin; an approach to pendulous. 

 Appleworts. An English name proposed for 



the order Pomacece. 



Appressed. Placed close upon something 

 else; when hairs lie flat upon the surface 

 of a plant they are said to be appressed. 

 Synonymous with adpressed, which see. 

 Approximate. Parts which are close to- 

 gether, but not united. 

 Aptandraceoe. Out of the genus Aptandra, 

 Mr. Miers has proposed to form a natural 

 order bearing this name. Only one spe- 

 cies is known, a tree with alternate 

 leaves and minute flowers, a native of the 

 banks of the Eiver Amazon. It is usual- 

 ly referred to Humiriads. Its great fea- 



AEA 



ture is having anthers opening by re- 

 flexed valves, as in Lauracece. 

 Apterous. Without the membranous mar- 

 gins which botanists call wings. 

 Aquatic. Applied to all plants which grow 

 in the water, whether they are entirely 

 submerged, float on its surface, or, hav- 

 ing the roots fixed in the soil, raise their 

 leaves and flowers above the water, as the 

 Water Lilies, (Nymphcea.) 



Aquifoliacece, (Ilicinece, Holly worts.) The 

 common Holly Tree is the type of a small 

 natural order of shrubs and trees, with 

 rotate monopetalous flowers, a definite 

 number of epipetalous stamens, and a 

 fleshy fruit. The species may be said to 

 possess in general emetic qualities, vari- 

 ously modified in various instances. Bird- 

 lime is obtained from the bark of the 

 common Holly, and the beautiful white 

 wood is much esteemed by cabinet-mak- 

 ers for inlaying. A decoction of Ilex vom- 

 itoria, called Black Drink, was used by the 

 Creek Indians at the opening of their 

 councils, and it acts as a mild emetic. 

 But the most celebrated product of the 

 order is Mate, or Paraguay Tea, the dried 

 leaves of Ilex Paraguay ensis. The old ge- 

 nus Aquifolium, now Ilex, is the type of 

 this natural order. 



Aquilariacece, (Aquilariads.) These consist 

 of fragrant tropical Asiatic trees, with 

 small, apetalous flowers, resembling 

 those of a Rhamnus. Only ten species 

 are known, of which the most important 

 is the genus Aquilaria. 



Aracece, (Aroidece, Arads.) These are in- 

 complete plants of the Endogenous class, 

 with numerous naked unisexual flowers, 

 closely packed upon a spadix, shielded 

 when young by the hooded leaf called a 

 spathe, as is seen in the common Wake- 

 robin, (Arum maculatum.) They are com- 



