DICOTYLEDON ES 



415 



Order II. Piperales 



These are for the most part 

 tropical herbs or woody climb- 

 ers, with extremely simple 

 flowers, in dense spikes, and 

 broad leaves which suggest 

 the Aracese. The arrangement 

 of the vascular bundles in the 

 stem, especially in the genus 

 Peperomia, is also like that 

 of the Monocotyledons. The 

 flowers are usually hermaph- 

 rodite, but may be diclinous 

 (Nematanthera). They are 

 quite destitute of floral enve- 

 lopes, and arranged in the axils 

 of bracts, upon a thick spike 

 (Fig. 390). 



Peperomia differs from all 

 other Angiosperms yet investi- 

 gated, in having the number 

 of nuclei in the embryo-sac 

 sixteen instead of eight. 



The fruit is a dry capsule 

 (Saururus) , or a berry (Piper), 

 and the seeds are characterized 

 by the development of abundant perisperm, in addition to the scanty endosperm. 



The order is represented in the United States by Saururus (Fig. 393) 

 and Anemopsis, the latter being Cali- 

 fornian. Anemopsis has the spike 

 subtended by petal-like bracts, sug- 



FIG. 394. Salixsp. A, male, B, female, inflores- 

 cence. C, male flower. D, female flower. 

 E, section of ovary. F, dehiscing ripe fruit. 

 G, seed. 



FIG. 395. Pnpulns trichocarpa. Male 

 flowers enlarged. A, B, show the 

 subtending, fringed bract. 



gesting the spathe of the Araceae. 

 There are three families, Pipe- 

 racese, Saururaceae. and Chlorantha- 

 cete. 



FIG. 396. Myrica (Comptonid) aspleni- 

 folia. (After BRITTON and BROWN.) 



