Ser. MblanospeemejE. Fam. Dicti/oka. 



Plate CXXVIII. 



PUNCTARIA PLANTAGINEA, Grev. 



Gen. Char. Frond undivided, membranaceous, fiat, ribiess, with a naked, 

 scutate root. Fructification scattered over the whole frond, in minute, 

 distinct dots, composed of roundish, prominent spores, intermixed 

 with club-shaped filaments. Punctaeia (Grev.), — from punctum, a 

 dot ; the fruit being in dots, scattered over the surface. 



Punctaeia plantaginea; frond lanceolate or obovato-lanceolate, cuneate 

 and gradually attenuated at base, brownish olive, coriaceo-membra- 

 naceous. 



Punctaeia plantaginea, Grev. Alg. Brit. p. 53. t. 9. Hook. Br. Fl. vol. ii. 

 p. 278. Harv. in Mack. FL Hib. part 3. p. 175. Harv. Man. p. 33. Wyatt, 

 Alg. Damn. no. 206. Endl. 3rd Suppl. p. 25. 



Diplostromium plantagineum, Kiitz. Phyc. Gen. p. 298. 



Zonaeia plantaginea, Ag. Sp. Alg. vol. i. p. 138. Ag. Syst. p. 268. Spreng 

 SysL Veg. vol. iv. p. 326. 



Ulva plantaginea, Both, Col. Bot. vol. ii. p. 243 and vol. iii. p. 326. E. Bui. 

 t. 2136. 



Ulva plantaginifolia, Widf. Crypt, no. 3. Lyngb. Hyd. Ban. p. 31. t. 6. 



Laminaeia plantaginea, Ag. Syn. p. 20. 



Hab. On rocks and stones, between tide-marks, and in rocky tide pools ; 

 occasionally on Algae. Annual. Spring and summer. Not uncom- 

 mon on the English and Irish coasts. Frith of Forth, Dr. Greville. 

 Orkney, Rev. J. H. Pollexfen. Calf Sound, Orkney, in four fathom 

 water, Lieut. Thomas and Dr. Mc Bain. 



Geogr. Distr. Atlantic shores of Europe. 



Descr. Root small, scutate. Fronds densely tufted, from four to twelve inches 

 in length, varying in breadth from less than a quarter of an inch to more 

 than two inches, lanceolate or ovato-lanceolate, more or less tapering to an 

 obtuse or subacute point, cuneate and very much attenuated below, passing 

 by insensible gradations into a minute, setaceous stem. In a young state- 

 both surfaces of the frond are clothed with exceedingly tender, subgelatinous, 

 transparent filaments, which give it a peculiarly soft feel, and make the 

 substance appear much thicker than it really is. These gradually wear off 

 as the plant attains its full size. The colour varies from a deep olive to a 

 reddish brown. The surface of the frond is beautifully areolated, the larger 

 cells of the interior being seen through those of the outer coat. Dots of 

 fructification, scattered over the whole surface, very minute, somewhat ob- 

 long, consisting of several elliptical spores, occasionally accompanied by a 

 lew short filaments. Roundish spore-like organs (antheridia?) are found on 

 tin- same plants that produce the regular fructification. They are of larger 

 size than the true spores, irregularly placed, depressed, pale coloured, and 

 contain a granular matter. 



