SUBDIVISION SECOND. 



ENDOGENS, OR MONOCOTYLEDONOUS PLANTS. 



Stem not distinguisliable into bark, pith and concentric zones or 

 layers of wood. Growth by irregular, internal accretions, consist- 

 ing of bundles of woody fibre and vessels, successively descending 

 from the leaves above, through the cellular tissue already formed. 

 Leaves mostly with simple, parallel veins, alternate, entire, frequently 

 sheathing at base, and seldom falling off by an articulation. Sepals 

 and PETALS, when present, commonly in 3s. Ovules produced within 

 an ovary. Embryo with one cotyledon, rarely with two, the second 

 being much smaller than, and alternate with, the first. 



CLASS III. AGL.UMACEOUS ENDOGENS. 



Flowers without glumes. Organs developed on the usual and 

 normal plan, consisting of stamens and pistils, either or both, sur- 

 rounded by verticillate, floral envelops ; or the latter are wanting, 

 and the stamens and pistils are achlamydeous. 



Order CXXXIY. ARACEJE.— Arads. 



Herbs or tropical shrubs, ^yith a fleshy rhizoma or cormus. 



Lv3. sheathing at base, often with branching veins, and sometimes compound. 



FIs. mostly monojcioua and achlamydeous, arranged upon a naked or spathaceous spadix. 



Perianth, when present, consisting of 4— 6 parts. 



Sta. definite or indefinite, hyposynous, very short. Anth. ovate, extrorse. 



Ova. free, 1— several-celled. Stig/)ui sessile. 



Fr— Berry succulent or dr>'. Seeds solitary or several, with fleshy albumen. 



Genera 26, species 170, abundant in tropical regions, more rare in temperate, one only, Calla palustris, 

 extending to the northern frigid zone. 



Properties.— An acrid, volatile principle pervades the order, which is, in some instances, so concen- 

 trated as to become poisonous. The corms and rhizomas abound also in starch, which in some cases, 

 when the volatile acridity is e-xfjcllcd in drying or cooking, is edible and nutritious. 



Conspectus of the Genera. 



\ Berry l-seeded. . Peltandra. 2 



i and covered ^ cylindric. \ Berry many-seeded. Calla. 3 



< with flowers. ^ oval, preceding the leaves. . Symplocarpus. 6 



^Spadi.\ in a snathe f and naked above. Stem a corm. . . . Artim. 1 



^ broad. < Spadi.x naked, yellow, on a clavate scape. Orontium. 4 



Leaves ( linear-ensifurm. Scape leaf like, ypadi.x lateral. Acorna. 5 



1. ARUM. 



Coptic aron, the name of the Fgyptian species, A. colocajiia. 



Flowers sometimes 9 cf • Spathe cucullatc, convolute at base ; 

 perianth ; spadix cylindric, naked above, staminate below the mid- 

 dle and pistillate at the base; berry 1 -celled, many-seeded. — %. 



1. A. THIFHYLMM. Draiion-Iinnf . Jark-iv-tfu-PiiIpH. 



Acaule.sceiit; /r.v. tril'oliatt', inostlv in pairs, loaflct.s oval, acuminate; spa- 

 dix clavate; spnihc ovate, acuminate, fiat and dctlcctcd above. — A curious and 

 well known inhabitant of wet woodland.s, Can. to Car. W. to the Miss. The 

 stem is a rugose, lieshy, .subterraneous conn giving off radicles in a circle from 

 44* 



