Ser. Melanosperme^e. Fam. Dictyotea. 



Plate XIX. 



HALISERIS POLYPODIOIDES, Ag. 



Gen. Char. Root, a mass of woolly filaments. Frond flat, linear, mem- 

 branaceous, with a mid-rib. Fructification : ovate spores, forming 

 distinct sori, or groups, mostly arranged in longitudinal lines. Grev. 

 Haliseris — from aks, the sea, and o-epu, endive. 



Haliseris polypodioides ; frond dichotomous, entire at the margin, plane; 

 spots of fructification linear, disposed along the mid-rib. 



Haliseris polypodioides, Ag.Sp.Alg. vol.i. p. 142. Syst. p. 262. Spreng. Syst. 

 Veg. vol.iv. p. 328. Grev. Jig. Brit. p. 64. t. 8. Hook. Br. M. vol. ii. 

 p. 283. Mack,Fl.Hib. part 3. p. 178. Wyatt, Alg. Da nm. no. 12. Harv. 

 Man. p. 30. Kiitz. Phjc. Gen. p. 340. t. 23. Mont. PI. Cell. Canar. p. 148. 



Dictyopteris polypodioides, Lamx. Journ. Bot. p. 19. sec. Ag. 



Dictyopteris elongata, Lamx. I.e. p. 18. sec. Ag. 



Fucus polypodioides, Desf. Ft. Atl. vol. ii. p. 421. Lamx. Bid. p. 32. t.24. f.l. 



Fucus membranaceus, Stack. Ner. Brit. p. 13. t. 6. Turn. Syn. Fuc. vol. i. 

 p. 141. With. vol. iv. p. 93. E. Bot. 1. 1758. Turn. Mist. t. 87. 



Fucus ambiguus, Clem. Fss. p. 310. 



Ulva polypodioides, Bee. Fl. Fran. vol. xi. p. 15. 

 Hab. On rocks and stones in the sea, from two to five fathoms. Perennial. 

 Summer and A.utumn. Rare. Several places along the southern 

 shores of England, where Mr. Stackhouse first gathered it. Shields, 

 Mr. Winch. Miltown Malbay, W.H.1L (1831). Youghal, Miss 

 Ball. Eoundstone Bay, Mr. McCalla. Jersey, Miss White ; Miss 

 Turner. 



Geogr. Distr. Atlantic and Mediterranean shores of Europe. North of 

 Africa, Desf. Ceylon, Herb. Linn. South Africa, Ecklon. Bahia, Martius. 

 Canary Islands, very rare, Despreaux. 



Descr. Root a callous disc, densely covered over with finely divided, tough, 

 matted fibres. Fronds growing in tufts, 4-12 inches high, about half an 

 inch wide, linear, several times dichotomous, the axils patent, traversed by 

 a dark coloured, filiform mid-rib, which is very strong below, and becomes 

 gradually thinner upwards. The apices of the segments are obtuse or 

 emarginate, in which case the tip of the mid-rib is forked. The margin is 

 flat, and entire. The membrane of the frond is rather rigid, thin, and 

 tears with great facility in an oblique direction from the margin to the 

 mid-rib, and the lower parts of full grown fronds are very generally much 

 lacerated. Not unfrequently proliferous shoots arc produced, especially 

 from old, weather-beaten plants, at points along the mid-rib. Fructification 

 of two kinds has been observed, on distinct individuals. The first and 

 regular kind consists in oblong sori or groups of elliptical spores 1 ying 

 close at either side of the mid-rib ; the second in scattered single spores ( P ) 

 of larger size than the former, dispersed over the frond. Colour, a clear 

 olive-green, with a tinge of yellow ; becoming foxj in age, and darker in a 

 dry state. Smell when freshly gathered, strong and disagreeably pungent. 



