HOBNWOBT PUEPLE LOOSESTEIFE. 113 



Pedunculated Starwort ; it grows only in Sussex, and I have 

 no specimen. These are all the members of the Mare's-tail 

 group. 



The Hornwort group comes next. Fanny found one member 

 of its only genus in the same fruitful ditch on Kenmoor. The 

 common Hornwort (Ceratophyllum demersum), has long stems 

 thickly beset with compound bristly leaves, at the foot of 

 which are whorls of tiny flowers. These have many stamens, 

 but they are borne on one petalless flower, and the sessile 

 stigma on another. The fruit is crimson, with a horn at the 

 end. 



The only other British species, the Unarmed Hornwort 

 (C. submersum), is distinguished by having no horns on its 

 seeds. 



Edward has specimens of some of the LOOSESTEIFE order. 

 In this tribe the calyx is tubular ; cloven into twelve teeth. 

 There are six petals, and the stamens are either six or twelve. 



The Spiked Purple Loosestrife (Lythrum salicaria, Plate 

 VIII., fig. 3), is a very handsome plant, growing four feet high, 

 with long lance-shaped leaves placed opposite to each other, 

 squarish stems, and spikes of crimson flowers set on in whorls. 

 It grows by streams and in watery places, flowering in July 

 and August. He has gathered it on the banks of the Avon, in 

 "Warwickshire, and in watery places about Hawkhurst, Kent. 



The Hyssop-leaved Purple Loosestrife is a smaller plant, in- 

 habiting much the same situations as the Willow-leaved species, 

 but its flowers are less brilliant in colour, as well as smaller ; 

 and it is very rare. We have no specimen. 



The Water Purslane (Peplis portula), is a very insignificant 

 plant. It grows from one to two inches high, with red stems, 

 and broad, glossy, opposite leaves. The tiny flowers with their 

 bell-shaped calices and six minute petals, are seated in the 

 axils of the leaves. The plant grows in shallow water ; when 

 the water dries up its stem and leaves become entirely red. 

 My specimens were gathered in and near a pond at Hawkhurst ; 



