BRITISH JUNGERMANNI^ 
( J. Mackaii.J 
JUNGERMANNIA MACKAII. 
(TAB. LIII. ) 
Jungermannia, surculo repente, vagfe ramoso: foliis distichis, imbricatis, bilobis; lobis inaequalibus ; 
superioribus majoribus, rotundatis ; inferioribus minutis, involutis : stipulis magnis, rotundatis, 
obcordatis : fructu laterali terminalique ; calycibus obcordatis, depressis, triangularibus ; ore 
contracto, elevato, dentato. 
Hab. Sent to me, January, 1812, by Mr. Mackay, who observed that he had known the 
plant to grow at the Dargle, for several years, and that it is not unfrequently mixed with 
J. serpyllifolia. — On wood, stones, and stems of heath, about Ballylicky, near Bantry. 
Miss Hutchins. — Lowdore. Mr. Lyell. — 'Upon rocks at Cheddar, Somersetshire, plentiful ; 
and on the rocky sides of the chasms and vallies in the neighborhood of Torquay ; and, 
indeed, in similar situations throughout the Lime-stone country, in that part of Devon. 
It occurs more rarely upon schistus, near the w'ater-fall at the Devil’s Bridge, Lidford. — 
Mr. Lyell finds it at Mount Edgecombe. — Sometimes it is attached to trees. — (In February 
and March, the fruit, both male and female, is produced in Devonshire.— In Ireland, 
Miss Hutchins finds capsules in November.) 
Plant growing in dense, blackish-green patches of various dimensions, from one or two inches 
to as many feet in diameter. 
Roots issuing from the lower surface of the stem, and immediately below the stipules, in 
small bundles, which consist of short, pellucid, fibres. 
Stems creeping over each other in successive layers, and closely appressed to the surface 
upon which they grow : each individual is from half an inch to an inch and a half in 
length, slender, filiform, flexuose, once or twice branched in an irregular, though 
somewhat pinnated, manner, the branches very variable in length : the substance is rather 
opaque; the cellules sufficiently apparent; the color a dirty green, approaching to brown. 
Leaves rather closely imbricated in two rows over the whole upper surface of the stem, 
horizontal, divided into two very unequally-sized lobes, of which the largest is about four 
tenths of a line in length, smaller as they approach the apex of the barren stem, though 
the reverse is the case in the fertile ones; of a roundish figure, slightly convex above;, 
the lesser one is scarcely one tenth of its size, involute, and ventricose (f. 4) : the texture 
is somewhat firm, the reticulation (as in the calyx represented at fig. 9) formed by 
