The President's Address. By Lord Avehury. 147 



A remarkable feature in the flowering of rushes is that it 

 occurs in pulses. For some days, perhaps, no flowers will be open ; 

 then, suddenly, without apparently any change in the weather to 

 account for it, the flowers will all open together. The feature is 

 especially marked in the species which have single, or few flowers. 

 For wind-fertilised species the arrangement is obviously advan- 

 tageous. The flowers open once for all. 



Luzula (Wood-rush). — The capsules are 1-celled, with only 

 three seeds, one for each carpel. The seeds are much larger 

 than in Juncus. 



Those of L. campestris have a marked prolongation of the 

 testa at the base ; those of L. Forsteri, on the contrary, at the 

 apex. 



Typhace.e. — The Typhaceas are monoecious wind flowers. 

 The fruit is a small seed-like nut of one or two carpels, 1 or 

 2-celled, with a solitary pendulous seed in each cell, on a long 

 thread-like stalk, which bears long silky hairs, insuring dispersal 

 by the wind. The albumen is copious. 



The order is a very small one, comprising only sixteen species, 

 of which seven are British. They are distributed over Europe, 

 temperate and tropical Asia, Australia, and the temperate parts of 

 North America, in shallow streams, ponds, and marshes. 



In Britain we have two genera, Typha and Sparganium ; the 

 former with two, the latter with three or perhaps five species. 



Typha (the Eeed-mace). — The inflorescence is a cylindrical 

 spike, sometimes interrupted in the middle, with male flowers 

 above and female below. The fruit is reduced to a single carpel 

 with one seed, having a striated testa, and conforming to the cavity 

 of the carpel. They are small, densely packed, terminated by a 

 long style, and enveloped in a copious down (fig. 27), and the 

 whole is so fluffy, or chaffy, and light, that it is easily blown about 

 by the wind, or by the water, on which the seeds would float. 



Sparganium (Burr-reed). — In Sparganium the flowers form 

 globular heads, placed at intervals along the summit of the stem, 

 with leaf-like bracts under the lower ones. The upper heads 

 are male, the lower ones female, consisting of sessile ovaries, each 

 surrounded by three or six scales, forming a perianth. 



Each fruit consists of one or two carpels, and when mature 

 consists of an ovoid seed, on a cuneate base, as If stalked, and 

 terminating in a beak, which is 1- or 2-celled, thick-walled, spongy, 

 and indehiscent. 



S. ramosum has the inflorescence branched and the beak short, 

 as it is also in S. mini mum. In S. simplex it is much longer. 



Auoide.e. Summary of the Order.— Though represented in 

 Britain by three species only, the order is a large one, including 

 98 to 100 genera and 900 or more species, abounding in the tropics 

 of both hemispheres, climbing to the tops of tall trees, and forming 

 the chief constituent of the lianes of tropical forests. Many of them 



