HYDROCHARIDACEyE 



139 



Order XC. Trilliacece (1 genus) 



Herb Paris — Paris quadrifolia 



(Plate XCII) 



This is the only British species of its Order, 

 and is easily recognisable by its creeping root, 

 simple stem, 4 whorled and veined leaves (less 

 frequently 3 or 5), and terminal green flower. The 

 perianth is composed of 8 or 10 narrow segments, 

 with an equal number of stamens ; and the ovary 

 has 4 or 5 cells, and an equal number of free 

 stamens. The berry is blue-black. The plant 

 grows in shady woods and thickets, but is not very 

 abundant. It is a dangerous poison. It flowers 

 in May and June. 



Yams. The only British species is the Black 

 Bryony (Tamus communis), which is a beautiful 

 hedge-plant, with some resemblance to the Red 

 Bryony (our Plate XL) in general appearance, 

 though the large heart-shaped leaves are undivided, 

 the flowers are much smaller, greener,with a 6-lobed 

 perianth and 6 stamens, and are succeeded by a 

 close cluster of rather large berries, first green and 

 then red. It is a poisonous plant, like the Red 

 Bryony, and the fresh root will raise a blister. 

 The extract or tincture is employed in dropsy and 

 chronic bronchitis. 



Sub-class II. Floridae 



Leaf-veins parallel, flowers without glumes. 



Order LXXV. Dioscoreacece (1 genus) 



This is a small family of climbing plants, rising 

 from a thick and often tuberous root-stalk. The 

 species of the typical genus Dioscorea are cultivated 

 like potatoes in tropical countries, and are called 



Order XCI. HydrocJiaridacecz (3 genera) 



A small family of plants growing in or under 

 water, of which there are three species in 

 Britain. The leaves are sometimes long and 

 narrow, but at other times broad. The flowers 



