128 POLEMQNIACE^, BORAGfN/E. [chap. 



Menyanthes and Limnanthemum (Kuhn, Bot. Zeit., 

 1867) are said to be dimorphous. 



POLEMONIACE^. 



This family is represented in England by one species, Polemon'mm 

 ccsruleum, and even tliis is a. doubtful native. It has been shown by 

 Axell to be proterandrous. 



BORAGINACEiE 



This order is easily distinguished from all others, 

 except the Labiatae, by the four seed-like nuts ; 

 from the Labiatae by the form of the flowers, and 

 by the leaves being alternate. It contains eleven 

 British genera, viz , — Echium, Pulmonaria (Fig. 96), 

 Mertensia, Lithospermum, Myosotis, Anchusa, Lycop- 

 sis, Symphytum, Borago (Fig. 95), Asperugo, and 

 Cynoglossum. 



In consequence of its conspicuousness, and the 

 easy accessibility of its honey, Echium vulgare is 

 visited by a great variety of insects. The flower is 

 tubular, contracting towards the base, so that insects 

 are naturally conducted to the honey. The stamens 

 are five in number; one remains in the tube of the 

 flower, while the other four project, and form a con- 

 venient alighting stage for insects, which can thus 

 hardly fail to dust their undersides with pollen. 



Echium is proterandrous ; when the flower opens 

 the anthers are already ripe ; the pistil, on the other 

 hand, is still quite short and immature, scarcely 

 reaching to the mouth of the tube. Gradually, how 

 ever, it extends until it reaches 10 mm. beyond 



