CLASSIFICATION OF ANGIOSPERMS. 233 



pressure or boiling with water, palm oil is obtained. The Cocoa- 

 nut pahn (Coais nncifera) yields the cocoa nut of the market 

 and is probably one of the most useful palms to the natives, fur- 

 nishing as it does, food, clothing, utensils of all kinds, building 

 materials, etc. The Sago-palms {Metroxylon Rumphii and .1/. 

 Icczx) yield sago, which is prepared by washing out the starch 

 from the cut stems and subsequently heating it. A tree 15 years 

 old yields from three to four hundred kilograms of sago starch. 

 The Date palm (Pluviii.v dactylifcra) yields the dates of the 

 market, and it is interesting to note that since very early times 

 the fruits produced by the growers in the Orient have been the 

 result of artificial or hand-pollination. 



III. ORDER ARALES OR SPATHIFLOR^. 



This order includes two families which are markedly different 

 in their habits: (ij The Aracese which are rather large herbs 

 with an in florescence known as a spadix and consisting of a fleshy 

 spike, v/hich is subtended or enclosed by a large bract known as 

 a spathe, as in the Calla-lily where it is large and white, and (2) 

 the Lemnaceffi or duckweed family, which is composed of minute, 

 floating, thalloid plants that develop one or more flowers on the 

 margin or upper surface of the thallus. 



ARACE^ OR ARUM FAMILY. The plants belonging 

 to this family are perennial herbs with tuberous or flesh}- rhi- 

 zomes and simple or compound leaves which are usually long- 

 petioled. The spadix is densely flowered, the staminate flowers 

 l)eing above and the pistillate below on the same axis, or the plants 

 are wholly dioecious. The perianth when present consists of 4 to 

 6 scale-like segments. Frequently the spadix is subtended or 

 enclosed by a more or less showy spathe. The fruit is usually a 

 berry, sometimes a utricle. 



A number of the plants of this family have medicinal proper- 

 ties and one of them yields the ofificial drug calamus (p. 496). 

 The drug is derived from sweet flag {Acorns Calamus) a plant 

 common in swamps and along streams in the Eastern United 

 States, and characterized by its long, narrow, linear, bilateral 

 leaves which are from two to six feet hisfh and one inch wide or 



