MYRTIFLOR^l. 



483 



bees and bees, which seek the nectar formed at the bottom of the recep- 

 tacle. Other species are only dimorphic, or even monomorphic Closely 



allied are, Nesasa, Diplusodon, Lagerstrosmia, and Cuphea, whose 

 flower resembles that of Lythrum, 

 but is zygomorphic. In Cuphea the 

 receptacle is oblique and at the 

 back prolonged into a spur, in which 

 the nectar, secreted by a gland 

 situated behind the ovary, is col- 

 lected ; the calyx and corolla gradu- 

 ally become reduced in size toward 

 the anterior side of the flower ; the 

 reverse, however, is the case with 

 the 11 stamens (the posterior one is 

 absent) ; the posterior loculus in the 

 bilocular ovary is sometimes barren ; 

 the fruit, when ripe, dehisces along 

 the posterior side, the ovary as well 

 as the wall of the receptacle being 

 ruptured by the placenta, which 

 expands and projects freely. The 

 flowers stand singly in the centre of the 

 stem, between the pairs of leaves. This 

 may be explained as follows : of the two 

 foliage-leaves in each pair, one supports a foliage-shoot, the other a flower ; 

 the foliage-shoot remains in the axil, but the flower is displaced through the 

 length of an entire internode to the next pair of leaves, and then assumes a 

 position between these two leaves. All foliage-shoots stand in two rows, the 

 flowers in two other rows. 



Pep Us (Water-purslane), a small, annual, plant, with thin, bell-shaped re- 

 ceptacle without projecting nerves. The small flowers have no petal-stamens, 

 and often also no corolla ; fruit indehiscent. Ammannia is closely allied to it. 



365 species ; 30 genera ; mostly in the Tropics, and more especially S. Am. 

 Some yield dy?s, e.g. Lawsonia inermis (cultivated in Africa and Asia) and 

 Lagerstrcemeria indica some contain tannin ; others are orn imental plants, 

 especially in gardens in warm countries. 



Order 2. Blattiaceae. 12 species. Tropical Asia and Africa. Trees. 

 Formerly included with Punica, but best placed as an independent order. 



Order 3. Melastomaceae. A very natural and very large order (150 

 genera; 2,500 species), its home being chiefly in tropical S. America, especially 

 the Brazils (termed by Schouw " The kingdom of Palms and Melastomacese "). 

 There are both herbaceous and arborescent species, which are easily recog- 

 nized by the opposite or verticillate, simple leaves which have (with the excep- 

 tion of a few heather-like species) 3-5-7-9 curved veins proceeding from the 

 base of the leaf, and connected very regularly by closely parallel, transverse 



FIG. 620. Lythrum salicaria. One 

 side of the perianth is removed from 

 all three flowers. A is long-styled, 

 mid-styled, and C short-styled. The 

 direction of the arrows and dotted 

 lines indicates the best (legitimate) 

 methods of crossing. 



