EXOGENOUS OE DICOTYLEDONOUS PLANTS. 



463 



891. Ord, RafflesiaceCC : parasitic flowers^ or flower-clusters (152), of 

 which the most striking is the gigantic Eafflesia Amoldi of Sumatra 

 (Fig. 150), perhaps as much related to the last order as to any. 



892. Ord. Nyctaginacese (Four-o'clock Family). Herbs or shrubs, 

 with opposite leaves ; distinguished by their tubular and funnel-form 

 calyx, the upper part of which resembles a corolla, and at length 

 separates from the base, which latter hardens and encloses the one- 

 celled achenium-like fruit, appearing like a part of it. Stamens liy- 

 pogynous, 1 - 20. Embryo coiled around mealy albumen (Fig. 616, 

 617) ; cotyledons large. Flowers involucrate. Mirabilis (Four- 

 o'clock) has a one-flowered involucre exactly like a calyx, while the 

 real calyx resembles the corolla of a Moi-ning- Glory. Abronia has 

 only one cotyledon to its embryo ! — Plants of warm latitudes ; many 

 occur on our Southwestern frontiers. 



893. Ord. Phytolaccacea; {Poke-iceed Family). Chiefly represented 



Fia 1086, 1087. Phytolacca decandra (Pokeweed). 1088 A flower. 1089. Unripe fruit. 

 1090. Cross-section of the same, a little enlarged. 1091. Magnified seed, 1092. Section of the 

 same across the emhryo. 1093. Vertical section, showing the embryo coiled around the albu- 

 men into a ring 1094. Magnified detached embryo. 



