152 FLOWERS OF LAKES, RIVERS, ETC. 



Arrow-head (Sa^ilUiria saoittifolia, L.) 



Rmiaiiis of ihis typical acjiialic and arclic type are found in hitcr- 

 glacial beds at West \\ iucrin;^ in Sussex. To-day it is found in 

 Arctic J'lurope (except Greece), N. Asia, X. W . India in the Nortli 

 Temperate and Arctic Zones. In Great Britain it is absent in Corn- 

 wall and N. Devon from the Peninsula province, and in the Channel 

 from the Isle of W'ioht, occurrino- throughout the Thames and An^jlia; 

 in the St:\crn, not in Momnouth; in .S. W'.des onK in Pembroke: in 

 N. Wales in Denbigh, I'lini, Anglesea; and in the Trent province and 

 Mersey except in Mid Lanes; in the Huniber province; only in 

 Durham in the iyne pnnince; not in the Isle of l\Ian in the Lakes 

 [)ro\ince, anel in Renfrew and Lanark. Elsewhere it ranges from 

 ("umbcrland to Kent and l)e\X)n. It is naturalizc;d in .Scotland, Icjcal 

 in Ireland. 



Arrowdiead is always the associate ot W'.iter Plantain, Mowering 

 Rush, and pondweeds of different kinds, being aquatic, and likewise 

 foimd in Ixilii still and running water, growing in ponds and lakes, and 

 also in rivers and streams. Canals are also a favourite habitat, since 

 they are intermediate between stagnant and llowing water. The plant 

 grows in the reed swamp. 



A floating plant with erect leaves and scapes only in later stages, 

 the Latin names and the English at once point to its main character- 

 istic, the arrow-shaped leaves, which are at first lance-shaped, with a 

 long point, with long lobes, borne on long 3-angled leaf-stalks. The 

 early submerged leaves are linear and streaming. The stems are 

 stoloniferous, the stolons or creeping shoots iorming winter bmls, ami 

 also, like the main stem, tubers. 



The (lowers are white on simple scapes, in whorls, with ])ur[)le 

 anthers in the centre, and the petals have also a purple; claw. The 

 male flowers are larger. The carpels are flattened at die sides and 

 winged. 



The plant is 2-8 in. in height. Arrow-head flowers from July 

 up to September, and is perennial, propagated by division. 



The llowers resemble those in ^Uisii/a, but are unisexual, diclinous, 

 racemose, and the male flowers are above the female. I he anthers 

 are purple and dehisce laterally, there being man\' stamens. The 

 female Howers are also variable. They are visited by (lies, and contain 

 honey. 



The carjiels are numerous, the smooth seeds falling when ripe 



