208 ALQM RHODOSPERMEjE. [Polysiphonia. 



ff Rigid ; dark-red or brown, strice numerous. 



12. P. atro-rubescens, Grev. Dark-red Polysiphonia. 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. Bot. t. 2340. P. 

 Agardhiana, Grev. Crypt, t. 210. and Harv. I. c. — P. badia, 

 Grcv. Harv. 1. c. ; and P. denudata, Grev. Harv. 1. c. p. 332. 



Rocky shores ; not uncommon. 2 — 6 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. 856. (excl.jig. 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 

 strias, 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. t. 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 decoinposito-pinnate character. Future observations 

 may prove it truly distinct. 



