Arum.] AKOIDE.E, 261 



Class II. ENDOGEN^E or MONOCOTYLEDONS. 



Monocotyledonous or Endogenous plants. Trunk formed of 

 cellular tissue and tubular vessels, which are irregularly scat- 

 tered, with no distinction, into bark, wood and pith, and desti- 

 tute of medullary rays: the oldest formation most external, the 

 centre the newest and softest. Leaves mostly alternate, often 

 sheathing, generally with parallel nerves. Flowers evident, 

 the parts of which they are composed mostly arranged in a 

 ternary manner ; the perianth very frequently single. Embryo 

 with one cotyledon ; if with two, then the accessory one is im- 

 perfect and alternate with the other. Plumule included within 

 the cotyledon, of which the opposite extremity usually en- 

 closes the radicle, and through which it bursts on germination. 



Subclass I. PETALOIDEiE. Lindl. 



Flowers with the segments of the perianth verticillate, in 

 one or two rows, or wanting and naked, not covered by imbri- 

 cated bracteas. 



Ord. 73. AROIDEiE. Juss. Lindl. Arum Family. 



Flowers monoecious, arranged upon a spadix, often naked. 

 Perianth 4 — G-parted, or wanting. Stamens definite or indefi- 

 nite, hypogynous, very short ; anthers 1 — 2- or many-celled, 

 ovate, turned outwards. Ovary free, 1- rarely 3-celled ; stigma 

 sessile. Fruit succulent or dry, not opening. Seeds solitary 

 or several ; embryo in the axis of fleshy or mealy albumen, 

 straight, cylindrical, with a cleft on one side in which lies the 

 plumule ; radicle next the hilum, rarely at the opposite extre- 

 mity. — Herbs or shrubs. Roots often tuberous or thickened. 

 Leaves sheathing at the base, with parallel or branching veins. 



1. Arum. Linn. Cuckow-pint. 



Spatha of one leaf, convolute at the base. Perianth none. 

 Spadix with germens at the base. Stamens (sessile) near 

 the middle of the spadix, which is naked above. Berry with 



