A RALES. J 



ARACEiE. 



127 



Order XXXVI. ARACE^.— Arads. 



Arofde^, Juss. Gen. 23. (1789) ; R. Brown Prodr. 333; Blume, Rimphia 1. 74 ; Endl. Gen. Ixxii. ; 

 Meumer, p. 360 ; Knnth enum.3.\% Martius in Bot. Zeitung, 1831, p. 449. Richard in Arch, 

 dc Bot. i. 11.— Arace-e, Schott Meletemata, 16. (1832), 



Diagnosis. — Aral Fndof/ens^toith numerous nahed floioers on a solitary spadix covered 

 by a simple hooded spatha, sessile anthers, loose seeds, and a slit axile embryo. 



Herbaceous plants, frequently with a fleshy corm ; or shrubs ; stemless or arborescent, 

 or climbing by means of aerial roots. Leaves sheathing at the base, convolute in the 

 bud, usually with branching veins ; 

 sometimes compoimd ! often cordate. 

 Spadix genei'ally enclosed in a spathe. 

 Flowers $ ^ > naked, arranged upon 

 the surface of a spadix, within a 

 spathe. $ : Stamens definite or indefi- 

 nite, hypogjTious, very short ; anthers 

 1- 2- or many-celled, ovate, turned 

 outwards. ^ , at the base of the spadix. 

 Ovary free, 1 -celled, very seldom 3- or 

 more-celled, and many-seeded ; ovules 

 erect or parietal, sessile, or attached to 

 long cords, orthotropal, campylotropal, 

 or occasionally anatropal ; stigma ses- 

 sile Fruit succulent. Seeds pulpy ; 

 embryo in the axis of fleshy or mealy 

 albumen, straight, taper, with a cleft 

 m one side, in which the plumule lies ; 

 (radicle obtuse, usually next the hilum, 

 occasionally at the opposite extremity. 

 R. Br.) Albumen sometimes wanting. 



The hooded spathe of the order of Arads 

 affords a character not to be mistaken, 

 and, coimected with theu' diclinous na- 

 ked flowers, gives them their most es- 

 sential diagnosis ; Bulrushes are dis- 

 tinguished by their long anthers and 

 want of spathe ; Screw-Pines by their solid 

 embryo and compound fruit ; and Duck- 

 weeds by then* reduction to the simplest 

 state in which flowering plants can exist. 

 The whole of these Orders, taken toge- 

 ther, are knowTi by their general ten- 

 dency to develop their flowers upon a 

 spadix, by their want of floral envelopes, 

 or by those parts not assummg the dis- 

 tinct forms of calyx and corolla, but 

 existing only in the state of herbaceous 

 scales. With the exception of Screw- 

 Pines, they are all also known by their 

 plumule lying within a cleft of the em- 

 bryo ; a structure found in few other 

 monocotyledonous plants, except Nai- 

 ads, in which the embryo is otherwise 

 widely different, and the hermaphrodite 

 Orontiacese, which are so much like 

 Arads in all but the combmation of 

 their sexes. 



Natives of all tropical countries abundantly, but of temperate clunates rarely 



Fig. LXXXVI. 



Fig. LXXXVII. 



In 



Fig. LXXXV.— 1. Spathe of Arum maculatum ; 2. its spadix loaded with flowers ; 3. an anther ; 4. a 

 transverse section of an ovary ; 5. a cluster of ripe fruits ; 6. a seed ; 7. a section of the same, showmg 

 the embryo. 



Fig. LXXXVI.— A single fruit divided vertically, so as to show the seeds in situ. 



Fig. LXXXVII. — A perpendicular section of one of the seeds. 



