Ser. Melanosperme^b. Fain. Fueea. 



Plate LXXXIX. 



PYCNOPHYCUS TUBERCULATUS, mtz. 



Gen. Char. Root composed of branching fibres. Frond cylindrical, dicho- 

 tomous. Air-vessels, when present, innate, simple. Receptacles ter- 

 minal, cellular, pierced by numerous pores, which communicate with 

 immersed, spherical conceptacles, containing, in the lower part of the 

 receptacles, parietal, simple spores, and in the upper, tufted antheridia. 

 Pycnophycus (Kiitz.), — from ttvkvos, thick, and <\>vkos, a sea-weed. 



Fycnophycus tuberculatus. 



Pycnophycus tuberculatus, Kiitz. Fkyc. Gen. p. 359 (1843). 



Cymaduse tuberculata, Dne. Ann. Sc. Nat., 1845. p. 12. 



Fucus tuberculatus, Huds. Fl. Aug. p. 588. Good, and Woodic. in Linn. 

 Trans, vol. hi. 198. Turn. Syn. Fuc. vol. ii. p. 505. Turn. Hist. t. 7. 

 Esper, I-c. Fuc. vol. ii. p. 20. t. 121. E. Bot. t. 726. Lamour. Ess. p. 20. 

 Stack. Ner. Brit, append. Ag. Sp. Alg. vol. i. p. 98. Ag. Syst. p. 279. 

 Spreng. Syst. Veg. vol. iv. p. 316. Gi'ev. Alg. Brit. p. 18. Hook. Br. Fl. 

 vol. ii. p. 269. Harv. in Mack. Fl. Hib. part 3. p. 169. Harv. Man. p. 21. 

 Wyatt, Alg. Danm. no. 103. Endl. 3rd Suppl. p. 29. 



Fucus bifurcatus, With. vol. iv. p. 109. t. 17. f. 1. 



Hab. In rock-pools left, on the recess of the tide, near low- water mark ; 

 never growing in places which are dry at low- water. Perennial. 

 Summer and autumn. Several places on the coast of Cornwall, Hud- 

 son, StacJchouse, Turner, &c. Ilfracombe, Bishop Goodenough. Bill 

 of Portland, Mr . Bryer. North of Ireland, Dr. Scott (sec Turn.). 

 Abundant on the west coast of Ireland, in several places, from Gal- 

 way to Cork. Jersey, Miss White and Miss Turner. 



Geogr. Distr. Atlantic shores of France and Spain. Coast of Barbary, Web. 

 and Molir. Cape of Good Hope, Boicie and W. H. H. 



Descr. Root, formed of branching fibres, which extend in patches from one to 

 several feet in diameter, over the surface of the rock. Fronds 12-20 inches 

 long, as thick as a goose-quill, cylindrical, erect, quite simple for the dis- 

 tance of from four to eight inches from the root, then forked ; and after- 

 wards repeatedly, but irregularly, dichotomous, one of the arms of the fork 

 being longer and stronger than the other, so that eventually the frond 

 often appears as if alternately branched. Axils obtuse, rounded. Vesicle* 

 frequently absent; when present, generally innate in the ultimate branches, 

 or immediately below one of the upper forkings. Receptacles terminating 

 the branches, from a prolongation of which they arc formed, simple, cylin- 

 drical, obtuse, composed internally of compaet cellular tissue; the cells 

 polygonal. They are, when ripe, tuberculated, each tubercle pierced In a 

 pore, beneath which is placed a spherical couceptacle. In the lower part of 

 the receptacle, the conceptacles contain numerous parietal, simple, elliptical 

 spores, narrowed at their lower end; in the upper part, thej are destitute 

 of spores, but filled with tufts of branching filaments, to whicb antheridia 

 are attached. Colour, when growing, a clear olive, more yellow, and semi- 



