Fig. 131. LAUEENCIA PINNATIFIDA. 



Colour. Properly a livid purple, or dull purplish red; but vaiyin^ from that to many 

 shades of green and yellow; the deeper the water in which it grows, the finer 

 the colour. 



Suhstance. Thick; elastic; fleshy; giving out a strong, disagreeable smell. 



Character of Frond. Compressed; narrow; tufted; very formally branched; all the 

 divisions as if imperfectly cut out of a flat surface {pinnatifid). Stems simple; 

 from one-twelfth to one-sixth of an inch across; often tapering to the base and 

 widening upwards; but sometimes the reverse. Branches long, alternate, up- 

 right; twice re-branched or oftener; each set one-third the length of the last; 

 the final ones short, obtuse, simple, or divided (Johed). Boot fibrous. 



Measurement. From 1 to 12 inches long. 



Fructification. Of two kinds. 1. Clustered sjjores in broadly ovate, unstalked (sessile) 

 cajjsules; external; on the corners of the smaller divisions. 2. Tetraspores 

 immersed in the brauchlets. 



Habitat. All round our coasts. On rocks from near high-water mark down to deep 

 water. Common. 



Increasing in luxuriance, as well as deepening in colour, the lower it grows : 

 miserably stunted and discoloured on rocks often exposed. There are two named 

 varieties (and many variations) : /3. osmunda and y. tennissima. In /3. osmunda 

 the branches are short and many times divided at the ends; in y. tennissima they 

 are very thin, much branched and widely spread. Among variations from the 

 character represented in the figure may be named that where the stem tapers at 

 the base, and the frond widens so much upwards, that the cutting out of the 

 upper branches is rather indicated than accomplished. Or instead of the lower- 

 most branches on the stem being longest, they will sometimes be shortest, so that 

 the plant becomes fan-shaped above. But the character of imperfectly cut out 

 branching prevails throughout. 



Fig. 132. LAURENCIA OBTUSA. 



Colour. Dull, semi-transparent red at first, quickly changing to a rosy pink, which 

 is very fleeting, and soon passes into the waxy yellow and white of decay. 



Suhsta/ice. Crisp when perfectly recent; soon becoming soft, and decomposing. 



Character of Frond. Cylindrical; branched; tufted. Stems as thick as a sparrow's 

 quill; undivided or somewhat forked. Branches long, irregularly set round the 

 stem (sometimes three or four from one level); the lowermost generally longest; 

 gradually shortening upwards; twice or thrice re-branched; each set diminishing 

 greatly in length. Last branchlets extremely short, mostly opposite or in 

 threes; almost horizontally set; narrowed at the base, widening upwards, blunt 

 at top as if swollen. 



3Ieasurement. From 3 to 6 inches long. 



Fructification. Of two kinds. Clustered spores in ovate capsules; external, on the 

 tips of the smaller branches. Tetraspores immersed in the ends of the final 

 branchlets. 



A¥hereas the frond of Laiirencia pinnatifida is characterized by being so entirely 

 at one level that its branches look as if they had been cut out rather than grown, 

 Laureneia ohtiisa is so entirely the reverse, that a fresh-gathered specimen stands 

 out in all directions, from the fact that its branches issue at various points round 

 the stem (fir-tree fashion). It is not often the plant is picked up otherwise than 

 the rosy pink usually described, for the process of decay soon begins when it is 

 once thrown ashore; but those who have met with it abundantly in its crisp 

 condition when quite recent, are aware that the beautiful colour it assumes soon 

 after, is the first stage of a change. It is by no means a pretty hue until exposed 

 for a short time, or plunged in fresh water. ■ 



58 



