PORTULACACE^ 



73 



Mare's Tail — Hippuris vulgaris 



(Plate XXXIX) 



This curious water-plant has perennial fibrous 

 roots, thrown off at the joints of the submerged 

 root-stalk, which is hollow and jointed, and some- 

 times grows to the length of 2 or 3 feet in still 

 water. The long narrow leaves are arranged round 

 the stem in whorls of from 8 to 12, and stand 

 out stiffly. The submerged leaves are drooping, 

 linear, and without veins. The ovary is placed 

 without a stalk in the axils of the leaves, and bears 

 a single style and stamen. When the sexes are not 

 united in the same flower, the upper ones are 

 generally male and the lower female. The plant 

 is widely distributed in ditches and ponds. 



Order XXXI. Cucurbitacece (1 genus) 



Red Bryony — Bryonia dioica 



(Plate XL) 



This is the only British representative of the 

 Order to which it belongs, and it is a common 



plant in hedgerows. The calyx is only half as 

 long as the corolla, and the flowers are of a greenish 

 white. The leaves differ considerably in form, and 

 are more or less lobate. The stem is slender and 

 climbing, and at each leaf-stalk rises a tendril which 

 at first is straight. Afterwards the front part twists 

 to the right, then towards the base, then to the left, 

 and then sometimes turns to the right again. The 

 berries are bright red, and, like the whole plant, 

 are poisonous. The root has been employed in 

 dropsy. 



To this Order belong Gourds, Cucumbers, 

 Melons, etc. Many species are edible, but others 

 are poisonous, and every unknown plant of the 

 Order should be regarded with suspicion. 



Order XXXII. Portulacacece (2 genera) 



A small Order in Britain, of which the different 

 species of Purslane {Portulaca), which are garden 

 herbs, are typical. They are South European 

 plants, more or less naturalised in Central Europe. 

 In Portulaca the leaves are more or less fleshy, 



