208 ALG^ RHODOSPERMWEjfc. \_Polijsipkmia. 



ft Rigid; dark-red or brown, striae numerous. 



12. P. atro-rubescens, Grev. Dark-red Poly siphonia. Fila- 

 ments sparingly branched, somewhat rigid ; branches very erect, 

 beset with short, subfasciculate or scattered subulate ramuli; 

 articulations variable ; lower, twice or thrice, upper once and 

 half as long as broad, multi-striate ; capsules ovate, pedunculate 

 or sessile. Harv. in Hook. Br. Fl. v. ii. p. 381. Conf. atro- 

 rubescens, Dillw. t. 70. C. nigra, E. Pot. t. 2340. P. 

 Agardhiana, Grev. Crypt. #.210. and Harv. 1. c. P. badia, 

 Grcv. Harv. I. c. ; and P. denudata, Grev. Harv. I. c. p. 332. 



Rocky shores ; not uncommon. 26 inches high, dark red, densely 

 tufted. With the consent of my friend, Dr. Greville, I gladly refer his 

 P. Agardhiana to this species ; and I feel no hesitation in adopting a 

 similar course with P. badia and denudata. 



13. P. violacea, Grev. Purple Polysiphonia. Filaments 

 flaccid, much and fasciculately branched upwards; branches 

 subdichotomous, patent; ramuli scattered, elongate, subsimple; 

 middle articulations 3 4 times, upper twice as long as broad ; 

 capsules shortly pedicellate, subovate. Hook. Br. Fl. v. ii. 

 p. 332. Hutchinsia violacea, Ag. Sp. Alg.v. ii.p. 76. Lyngb. 

 Hydroph. Dan. t. 356. (excl.fig. a.) 



Found among rejectamenta on the strand near Ballymacarret, April 

 10th, 1836 ; Dr. Drummond. Sparingly branched at the base, much 

 and fasciculately branched upwards ; branches long, patent, subdicho- 

 tomous, the secondary ones very erect, almost appressed, with roundish 

 axillae. Ramuli elongated, virgate, straight, simple, or with a few 

 ramular processes near the apex, often fibrilose. Articulations 5 7 

 striae, the basal ones very short, but rapidly elongating. Colour a dull 

 red. Substance flaccid, adhering to paper. Doctor Drummond's spe- 

 cimens are from 6 10 inches long, but destitute of fruit, which is 

 described by Dr. Hooker as being shortly pedicellate, ovate or sub- 

 urceolate, with an elongated but not contracted neck ; scattered over 

 the ramuli. 



14. P. nigrescens, Grev. Dark Polysiphonia. Filaments 

 robust, rigid below, much branched and bushy ; upper branches 

 somewhat pinnate with distichous, subulate ramuli, which are 

 mostly ramulose toward their apices ; lower articulations very 

 short, upper rather longer than broad; capsules ovate, sessile. 

 Harv. in Hook. Br. Fl. v. ii. p. 332. Conf. fucoides, Dillw. 

 t. 75. E. Bot. 1. 1743 Conf. nigrescens, E. Bot. t. 1717. 



Rocky shores, common. A very variable plant, and, perhaps, more 

 than one species is confounded under this name. Mrs. Griffiths has 

 communicated a beautiful variety (?}, from Larderham, which she is 

 inclined to consider a distinct species ; and I gathered a similar plant 

 at the Black Castle, Wicklow. In this all the branches are perfectly 

 distichous and remarkably patent, the stem is subcompressed, and the 

 whole plant has a decomposito-pmnate character. Future observations 

 may prove it truly distinct. 



