SUBDIVISION SECOXD. 



ENDOGENS, OR MONOCOTYLEDONOUS PLANTS. 



Stem not distinguishable 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. AGIiUMACEOUS ENDOGE]VS. 



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 CXXXIV. ARACE^.— Arads. 



Herbs or tropical shrubs, with a fleshy rhizoma or cormus. 



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



Fls. mostly monoecious and achlamydeous, arranged upon a naked or spathaceous spadix. 



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



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



Ova. tree, l — several-celled. Stigma sessi\e. 



Ft.— Berry succulent or dry. Seeds solitarj' or several, with fleshy albumen. 



Genera 2S, species 170, abimdant in tropical regions, more rare in temperate, one only, Calla palusUis 

 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. Tlie corms and rhizomas abound also in starch, which in some cases, 

 when the volatile acridity is expelled in drying or cooking, is edible and nutritious. 



Conspectus of the Genera. 



\ Berry 1-seeded. . Peltandra. 2 



I and covered $ cylindric. ( Berry many-seeded. Calla. 3 



. { with flowers, ; oval, preceding the leaves. . Symploearptis. 6 



> Spadix m a spathe ( and naked above. Stem a corm. . . . Arum. 1 



5 broad. ( Spadix naked, yellow, on a clavate scape. Orontium. 4 



Leaves { linear-ensiform. Scape leaf like. Spadix lateral. Acorua. ' 5 



1. ARUM. 



Coptic aron, the name of the Egyptian species, A. colocaiia. 



Flowers sometimes $ c?. Spathe cucullate, convolute at base ; 

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

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

 1. A. TRiPHYLLCM. Dragpn-Root. Jack-in-tlie-Pul'pit. 

 Acaule.scent ; Irs. trifoliate, mostly in pairs, leaflets oval, acuminate; spa- 

 di.v clavate ; spathe ovate, acuminate, fiat and deflected above. — A curious and 

 well known inhabitant of wet woodlands. Can. to Car. W. to the Miss. The 

 stem is a rugose, flesh};-, subterraneous corm giving off radicles in a circle from 

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