STRIARIA PUNCTARIA. 41 



IX. STRIARIA. Grev. [Plate 8, A.] 



Root naked and scutate. Frond filiform, tubular, continu- 

 ous, membranaceous, branched. Fructification : groups of 

 roundish spores forming transparent lines. Grev. Name, 

 from the transverse strife formed by the lines of fructification. 



1. S. attenuate*, Grev.; Hook. Br. FL ii. p. 279; Grev. 

 Crypt. Scot. t. 288 ; Grev. Alg. Brit. p. 55, t. 9 ; Wyatt, 

 Alg. Danm. No. 160; Harv. Phyc. Brit. t. xxv. 



Between tide-marks, and in 4 5 fathom water, growing on other Algae, 

 rare. Annual. Summer. Found all round the coast. Fronds tufted, 

 3 12 inches high, half a line to a line in diameter, set with many patent, 

 elongate, simple or sub-simple, mostly opposite branches, much attenuated 

 at both extremities, and sometimes bearing a second series of similar 

 branches. When in fructification the branches are marked, at spaces of 

 half a line asunder, with transverse rings or bands composed of clusters of 

 spores, sometimes accompanied with filaments. The substance is delicately 

 membranaceous, and the colour a pale olive. The branches are sometimes 

 irregularly scattered, sometimes, especially in the Devonshire plants, 

 whorled, 3, 4 or 5 in a whorl. This plant is also a native of the Medi- 

 terranean. 



X. PUNCTARIA. Grev. [Plate 8, B.] 



Frond undivided, membranaceous, flat, ribless, with a 

 naked scutate root. Fructification scattered over the whole 

 frond, in minute, distinct dots, composed of roundish, promi- 

 nent spores, intermixed with club-shaped filaments. Name, 

 punctum, a dot ; from the dot-like fructification. 



1. P. latifolia, Grev. ; frond pale olive-green, thickish, ge- 

 latinous and tender, oblong or obovate, suddenly tapering at 

 base. Grev. Alg. Brit. p. 52 ; Hook. Br. Fl. ii. p. 278 ; 

 Wyatt, Alg. Danm. No. 9 ; Harv. Phyc. Brit. t. viii. 



On rocks and Algae between tide-marks. Annual. Spring and sum- 

 mer. Sidmouth and Torquay, Mrs. Griffiths. Near Belfast, Dr. Drum- 

 mond. West of Ireland. Root a minute disk. Fronds generally tufted, 

 8 16 inches long, 1 3 wide, oblong or lanceolate, flat or curled, gene- 

 rally obtuse at both extremities, occasionally tapered, delicately membra- 

 naceous and semitransparent, somewhat gelatinous, of a pale olive-green 

 colour. Dots of fructification minute, roundish, scattered over both 

 surfaces. 



2. P. plataginea, Roth ; frond dark brown, coriaceo-mem- 

 branaceous, obovate, much attenuated at base. Grev. Alg. 

 Brit. p. 53, t. 9; Hook. Br. Fl. ii. p. 278; E. Bot. t. 2136 ; 

 Wyatt, Alg. Danm. No. 206 ; Harv. Phyc. Brit. t. cxxviii. 



