408 THE SPIDEEWOET AND THE PONDWEED FAMILIES, 



In opulent collections there are other superb plants of this family 

 called Heliconia and Strelitzia. 



CXXXVIL— THE SPIDERWORT FAMILY. Commelyndcece. 



A few beautiful garden flowers of liliaceous aspect are aU that 

 represent the Commelynaceoc about Manchester. The commonest is the 

 Spiderwort, or Tradescantia Virginica, distinguished by its numerous 

 succulent stems, rising in clumps a foot or more in height ; abundant 

 grass-like leaves, and terminating and sessile umbels of numerous 

 white, rose-coloured, or violet flowers. The calyx consists of three 

 green sepals ; the corolla of three large round petals, altogether an 

 inch across ; the six stamens are densely covered with beaded hairs of 

 the same colour as the petals, and are tipped with large, square, golden- 

 coloured anthers. The other species in cultivation belong to the 

 genus Commelyna. 



CXXXVIII.— THE PONDWEED FAMILY. Naiaddcecs. 



Aquatic plants with long and slender stems, either wholly siib- 

 merged, or floating upon the surface of the water. Leaves numerous, 

 varying in shape from linear to oval, alternate or opposite, petiolate or 

 sessile, and either sheathing at the base or accompanied by sheathing 

 stipules. Flowers inconspicuous, greenish, usually in spikes an inch 

 or two long, and elevated slightly and vertically above the surface of 

 the water ; occasionally axillary and solitary, and in some cases uni- 

 sexual. Perianth in four small segments, sometimes absent altogether j 

 stamens usually four, sometimes only two or one ; ovaries and stigmas 

 of the same number. The tetramerous flowers distinguish these plants 

 from all other aquatic Endogens ; and the pai'allel-veined leaves pre- 

 vent their being confounded with tetramerous Exogens. Fifty or 

 sixty species only are known, yet few parts of the world are without 

 their presence. A few belong to the sea. 



Twenty-two species are reputed wild in England, seventeen of them 

 being Potamogetons, but the genuine species of the latter are probably 

 only ten, reducing the total native representatives to fifteen. Eight of 

 the fifteen grow near Manchester. 



