98 HEPATICiE. [Riccia. 



6. Jungermannia. Common receptacle of the fruit none : 

 perianth or calyx monophyllous, tubular (rarely wanting) : 

 capsule 4-valved, terminating a peduncle which is longer than 

 the perianth. 



CRYPTOGAMIA HEPATIC^E. 



1. RfcciA. Linn, Riccia. 



Capsule sphserical, immersed in the frond, indehiscent, 

 (covered by a calyptra?), crowned with a style which alone is 

 protruded. (3Iusc. Brit. ed. 2. p. 211.) — Named in compliment 

 to Pietro Francesco Ricci, a Florentine botanist. 



1. R. crystdllina, Linn, (clirystalline Riccia); frond carnose 

 ovato-oblong 2 — 3-lobed, the divisions dichotomous. Muse. 

 Brit. , ed. 2. p. 212. — a. frond fleshy glaucous channelled, seg- 

 ments acute. R. glauca, Linn. Sp. PL p. 1605. E. Bot.t. 2546. 

 Hooker, Fl. Scot. P. II. p. 110. Lindenb. Syn. Hepat. p. 117. 

 — R. minima, Linn. Sp. PI. p. 1605. Dill. Musc.t. 78./ 10, 1 1. 

 — (3. frond thin nearly plane yellowish-green, segments obtuse. 

 R. crystallina, Linn. Sp. PI. p. 1605. — Lindenb. Syn. Hepat. 

 ^.116. Dill. Muse. t. 78./ 12. 



On banks, «. in rather dry situations. /3. in moist places, especially in 

 the mould of garden-pots in the greenhouse and stove, Bot. Garden, 

 Glasgow. Fr. March, Apr. — A careful examination of numerous speci- 

 mens, both fresh and dried, enables me to assert that the vars. above 

 named are all the same species, depending mainly on age and place of 

 growth for their different appearance. The first, «., including glauca and 

 minima, Linn., these being only dependent on age and size, grows in 

 comparatively exposed spots, and is small, fleshy, but little divided, 

 grooved along its upper surface, and of a glaucous green colour. The /3. 

 again, which is commonly called crystallina, inhabiting moister places, is 

 generally larger and thinner, with more numerous and obtuse segments 

 and a yellowish-green hue. In both the fronds grow in orbicular tufts, ra- 

 diating from the centre, and when fresh, have a remarkably clirystalline 

 appearance, owing to the delicate and pellucid nature of the cellules, not 

 unlike Mesembryanthemum crystallinum, which induces me to retain the 

 present specific appellation. 



2. R. ? fluitans, Linn, (iiarrow floating Riccia); aquatic float- 

 ing, frond thin repeatedly forked, with linear obtuse segments 

 generally notched at the extremity. Limi. Sp. PI. p. 1606. E. 

 Bot. t. 25 1 . Muse. Brit. ed. 2. p. 2 1.3. — Ricciella fluitans, Braun. 

 — Lindenb. Syn. Hepat. p. 115. Dill. Muse. t. 74./. 17. 



Stagnant waters. Not found in Scotland. Fr. . — Fronds half 



an inch to 2 inches long, yellow-green, repeatedly dichotomous, segments 

 linear, somewhat thickened, as if nerved in the centre grooved above 

 when dry, seinipellucid ; reticulation indistinct; extremities obtuse, 

 opaque, sometimes appearing spotted, as if with young fructification, 1 ac- 



1 Lindenberg describes the fructification as " Caps, globosa, in inferiori 

 frondis pagina sessilis, (circumcissa?). Setnina elateribus destituta." 



