Fig. 131. LAURENCIA PINNATIFIDA. 
Colour. Properly a livid purple, or dull purplish red ; but varying from that to many shades 
of green and yellow ; the deeper the water in which it grows, the finer the colour. 
Substance. 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, upright ; twice re-branched or 
oftener ; each set one-third the length of the last ; the final ones short, obtuse, 
simple or divided (lohed). Boot fibrous. 
Measurement. From 1 to 12 inches long. 
Fructification. Of two kinds. 1. Clustered spores in broadly ovate, unstalked {sessile) capsules; 
external ; on the corners of the smaller divisions. 2. Tetraspores immersed in the 
branchlets. 
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) : (i. osmunda and y. tenuissima. In /3. osmunda the branches are short and many 
times divided at the ends ; in y. tenuissima they are very thin, much branched and widely 
spread. Among variations from the character represented in the figure may he 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 lowermost 
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. 
Substance. 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 (some- 
times 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 hori- 
zontally set ; narrowed at the base, widening upwards, blunt at top as if swollen. 
Measurement. 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. 
Whereas the frond of Laurencia pinnatifida is characterized by being so entirely at one 
level that its branches look as if they had been cut out rather than grown, Laurencia obtusa 
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. 
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