60 FUCACEiE.— Saegasshm. iv. 



extend in all directions. In such specimens the base appears to be a fragment of 

 broken branch", rather than a true disciform root. Branches smooth, zigzag, or 

 angularly bent, once or twice divided in an alternate manner, the lesser branches 

 set with distichous leaves, having a vesicle in the axil of each. Leaves from two to 

 three inches in length and from one to three lines in width, coriaceous, sharply- 

 serrate, tapering to each end, furnished with a strong midrib, but usually destitute 

 of glandular pores. The serratures are often duplicate. Air-vessels very numerous, 

 about as big as peas, spherical, mostly mucronate, tipped with a longish bristle ; 

 their stalks about as long as the inflated part, and roundish. Receptacles rarely 

 found. Colour when quite fresh a pale and beautifully clear olive ; but soon 

 changing and becoming foxy in age and very dark in drying. Substance, when 

 living, brittle. 



This is the common Tropical Sea-grape, whose air-vessels, resembling berries, are 

 popularly taken for fruit. It has already been spoken of as the famous gulfweed 

 of navigators.* 



5. Sargassdm Liebmanni, J. Ag. ; " stem filiform, subterete, branched on all 

 sides ; leaves lanceolate, acuminate, ribbed, without glands, spinuloso-dentate, 

 waved and twisted ; air-vessels spherical, somewhat margined, pointed, on filiform 

 stalks shorter than themselves ; receptacles two-edged or triquetrous, serrato-dentate, 

 forked, their branches at length subpedicellate, agglomerated in the axil." J. Ag. 

 Sp. Alg. vol l.p. 326. 



Hab. On the Pacific coast of the Mexican Eepublic, Leibman. (v. s. in Herb. 

 T.C.D.) 



Stems or primary branches numerous, from a short stipe, a foot or more in 

 length, filiform, slightly flexuous, smooth, closely set with short, alternate, spirally 

 disposed, spreading branchlets. These branchlets in my specimen are an inch or 

 two in length, the lowest not longer than the upper, and issue at intervals of half 

 to three-quarters of an inch. Leaves an inch to an inch and half long, three or 

 four lines in breadth, somewhat lanceolate, obtuse, thick, leathery, waved and 

 curled, midribbed, almost destitute of glandular pores, sharply spinuloso-dentate, 

 the teeth deltoid-acuminate, patent, with rounded sinuses between. Air-vessels iew, 

 and only on the uppermost branchlets, on very short stalks, spherical, with a 

 narrow leafy border, and a small point or leafy mucro. Receptacles axillary, 

 densely tufted, repeatedly forked, three-sided, sharply spinoso-dentate, much shorter 

 than the subtending leaf. Colour dark brownish olive. Substance leathery, dense. 



6. Saegassum hystrix, J. Ag. ; " Stem filiform, subterete, branched on all sides; 



* Page 53. 



