THE APETALOUS ORDERS. 



467 



perfect or polygamous. Calyx campanulate, four- or five-cleft, 

 free from the ovary ; the lobes imbricated in aestivation. Stamens 

 inserted on the base of the calyx, as many as its lobes and oppo- 

 site" them, or more numerous. Ovary one- or two-celled, with a 

 single suspended ovule in each : styles or stigmas two. Fruit one- 

 celled and one-seeded, either a samara with a straight embryo and 

 no albumen, as in the Elm (Ulmus) ; or a drupe with a curved em- 

 bryo and scanty albumen, as in Celtis (Hackberry), the type of the 

 suborder or tribe CELTIDE^E. Timber-trees. The inner bark of the 

 Slippery Elm is charged with mucilage. Hackberries are edible. 



1020 



1023 



871. Ord, SaururaceSB (the Lizard's-tail Family). Herbs (grow- 

 ing in swampy places), with the stems jointed at the nodes ; the 



FIG. 1020. Saururus cernuua. 1021. A separate flower, with its bract and a part of the 

 axis magnified. 1022. A more magnified anther, discharging its pollen from one cell. 1023. 

 Cross-section of the ovary. 1024. Vertical section of one of the carpels in fruit, and of the con- 

 tained seed, with the sac at the extremity of the albumen, containing the minute embryo. 

 1025. A seed. 1026. Same, with the outer integument (testa) removed, showing the sac of the 

 amnios. 1027. The latter, highly magnified. 1028. Section of the same, showing the inclosed 

 heart-shaped embryo. 



