382 



EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



713. Ord, NelumbiaceSB (the Nelumbo Family}. Aquatic herbs, 

 with very large leaves and flowers, on long stalks arising from a 

 prostrate trunk or rhizoma, which has a somewhat milky juice : 

 the leaves orbicular and centrally peltate. Calyx of four or five 

 sepals, deciduous. Petals numerous, inserted in several rows into 

 the base of a large and fleshy obconical torus, deciduous. Sta- 

 mens inserted into the torus in several rows : the filaments peta- 

 loid ; the anthers adnate and introrse. Carpels several, separately 

 immersed in hollows of the enlarged flat-topped torus or recepta- 

 cle (Fig. 351), each containing a single anatropous ovule ; in fruit 

 forming hard, round nuts. Seed without albumen : embryo very 

 large, with two fleshy cotyledons, and a highly developed plumule. 

 Ex. The order consists of the single genus Nelumbium, em- 

 bracing two species ; one a native of Asia, the other of the United 



FIG. 512. Brasenia peltata (Water-shield) ; the lower flower with the floral envelopes and a 

 part of the stamens removed. 513. A magnified stamen. 514. A magnified carpel. 515. The 

 same divided lengthwise, showing the ovules attached to the outer or dorsal suture ! 516. Sec- 

 tion of a carpel, in fruit. 517. A magnified seed, with half the outer integument removed, dis- 

 playing at the upper extremity the bag which contains the embryo. 518. A magnified section 

 through the middle of the albumen, &c. ; bringing to view the minute embryo inclosed in its 

 sac, lying outside of the albumen, which forms the principal bulk of the seed. 



