CLASSIFICATION OF ANGIOSPERMS. 473 



medicine. Various species of Cyperus (C. scariosus, of the East 

 Indies, and C. pertenuis, of India) yield ethereal oils and are used 

 in making perfumery. Cyperus Papyrus is used in medicine and 

 also furnished the paper of the Ancients. 



IV. ORDER PRINCIPES. 



In this order is included that interesting group of tropical 

 and sub-tropical plants the PALMS (Palmae). They are arbores- 

 cent, having simple unbranched trunks which are terminated by 

 clusters of leaves, in the axils of which flowers are produced. The 

 leaves are pinnate (Feather Palms) or palmate (Fan Palms) 

 and often very large. The petiole is well developed, with an am- 

 plexicaul, more or less fibrous sheath. The inflorescence is usually 

 lateral, in some cases forming a large spadix with a woody, boat- 

 shaped spathe. In comparison the individual flowers are very 

 small. The fruit is either a berry, as in the Date palm, or a drupe, 

 as in the Cocoa-nut palm, generally i -seeded and with a large 

 horny or bony endosperm, as in the Date palm (p. 135) and 

 Phytelephas macrocarpa, the latter of which yields vegetable ivory, 

 used in the making of buttons (Fig. 258). 



The fruit of the saw palmetto [Serenoa (Sabal) serrulata], 

 one of the fan palms, is official. The saw palmetto is characterized 

 by having a creeping, branching root-stock or rhizome, one end 

 of which rises a short distance above ground, this portion being 

 surmounted by a dense crown of leaves. The petioles are slender 

 and spinose on the edges ; the blade is fan-shaped and consists of 

 a number of palmate divisions which are slightly cleft at the apex. 

 The inflorescence is densely tomentose and shorter than the leaves. 

 The fruit is a i -seeded drupe. 



The palms yield a number of useful products. The Betel-nut 

 palm (Areca Catechu) produces a seed having medicinal proper- 

 ties (Fig. 259). The seeds, known as ARECA NUT, are 20 to 25 

 mm. long, conical, grayish-brown, with numerous spiral, reddish 

 veins, heavy, hard, somewhat aromatic, astringent, and slightly 

 acrid. They contain about o.i per cent, of an oily liquid alkaloid, 

 arecoline, which chemically and in its physiological action resem- 

 bles pelletierine ; 14 per cent, of tannin, resembling catechutannic 

 acid; gallic acid; a red coloring principle; and 14 per cent, of a 



