500 MANUAL OF NATURAL HISTORY. 



of hurtful species is comparatively few, these being 

 principally found among the Melanthiacece, and some 

 of the Aracece. 



IV. CLASS..— ENDOGENS (Endogenss). 



Wood of stem and of root, arranged in a confused 

 manner, the youngest in the centre ; leaves straight- 

 veined, permanent ; organs of fructification ternary ; 

 embryo monocotyledonous ; germination endorhizal. 



I. SUB-CLASS. — Bisexual-Endogens (Diphysese). 

 Flowers hermaphrodite ; perianth present. 



I. TRIBE. — Hypogynous-Endogens (Phylleleutherae). 

 Flowers free from the ovary, rarely perigynous. 



I. ORDER — Alismals (Alismales). 



Perianth 3-6-divided ; carpels separate ; albumen 

 none. 



1. Family. — Arrow-grasses (Juncaginacese). Her- 



baceous ; leaves parallel-veined ; flowers in- 

 conspicuous, scaly, white or green, in spikes 

 or racemes ; sometimes perianth ; stamens 

 six; anthers extrorse ; carpels 3-4-6 ; ovules 

 1 -2 ; placentae axile or basal ; fruit dry, 1-2- 

 seeded ; embryo slit on one side ; plumule 

 very large. Marshy and aquatic plants, in 

 most parts of the world. 



2. Family. — Water-plantains (Alismacese). Her- 



baceous ; leaves narrow or expanded ; flowers 

 in umbels, racemes, or panicles, very rarely 



