Ser. Melaxosperme^e. Fam. Fucetz. 



Plate LXVI. 



HALIDRYS SILIQUOSA, Lyngb. 



Gen. Char. Frond compressed, linear, pinnated with distichous branches. 

 Air-vessels lanceolate, stalked, divided into several cells by transverse 

 partitions. Receptacles terminal, stalked, cellular, pierced by nume- 

 rous pores, which communicate with immersed spherical conceptacles, 

 containing* parietal spores and tufted antlieridia. Halldbys [Lyngb.) 

 — from a\s, the sea, and 8pvs, an oak. 



Halidrys siliquosa ; branches linear, very narrow j air-vessels compressed, 

 linear-lanceolate, slightly^constricted at the septa, mucronate. 



Halidrys siliquosa, Lyngb. Hyd. Ban. p. 37. Grev. Alg. Brit. p. 9. 1. 1. 

 Hook. Brit. Fl. vol. ii. p. 266. Wyatt, Jig. Banm. no. 53. Harv. in Mack. 

 Fl. Hib. part 3. p. 168. Harv. Man. p. 19. Endl. 3rd Suppl. p. 30. 



Cystoseira siliquosa, Ag. Sp. Alg. vol. i. p. 72. Ag. Syst. p. 287. Spreng. 

 Syst. Veg. vol. iv. p. 317. Grev. Fl. Edin. p. 285. 



Fucus siliquosus, Linn. Sp. PI. p. 1829. Syst. Nat. vol. ii. p. 716. Fl. Lapp. 

 p. 365. Gm. Hist. p. 81. t. 2. B. Fl. Ban. 1. 106. Huds. Fl. Ang. p. 574. 

 Light/. Fl. Scot. vol. ii. p. 921. With. vol. iv. p. 88. Good, and Woodw. 

 in Linn. Trans, vol. hi. p. 124. E. Bot. t. 474. Stack. Ner. Brit. p. 8. t. 5. 

 Turn. Syn. vol. i. p. 60. Hist. t. 159. Esper, Lc. Fuc. t. 8. 



Fucus siliculosus, Stack. Ner. Brit. t. 11. 



Hab. On rocks and stones in the sea, at and below half tide level. Peren- 

 nial. Winter and Spring. Common on the shores of the British 

 Islands. 



Geogr. Dist. North Sea, and Northern Atlantic. 



Distr. Root, a large, conical disc. Fronds, from one to four feet long or more, 

 linear, compressed, two-edged, from one to two lines in breadth, flexuous, 

 mostly undivided, distichously pinnate or bi-pinnate. Pinna alternate, erecto- 

 patent, issuing with an obtuse axil ; the lower ones much lengthened, and 

 either naked below, or furnished with a few small branchlets and air-vessels, 

 pinnate, or bi-pinnate above, the smaller divisions set with alternate vesicles 

 or with receptacles ; the upper pinnae gradually shorter, more simple, and 

 better furnished than the lower, and generally terminating in racemes either 

 of vesicles or of receptacles. Air-vessels linear, oblong, or lanceolate, sup- 

 ported on slender stalks, and tipped by a linear mucro of various length, 

 from a quarter inch to an inch and a half, and which sometimes bears at its 

 apex a receptacle. The air-vessels are externally marked with transverse, 

 constricting lines, very visible when dry, which correspond to internal septa 

 dividing the hollow inside into numerous distinct chambers, through 

 which run several longitudinal threads. Receptacles either forming racemes 

 at the apices of the branches, or terminating the mucronea of the vesicles, 

 lanceolate, subacute, on short stalks, distichous, compressed, furnished with 



