308 



FLQKA OF NEW ZEALAND, 



[Lichenes. 



the thallus, and well described by the authors above referred to. Mr. Spruce observes of it : — " Near Jurancon 

 there is a Collema on the trees which is quite meteoric ; in wet weather, and especially after thunderstorms, it 

 springs up as suddenly as a mushroom, forming globular tremelloid masses, covered with apothecia. Leon Dufour 

 has observed the same near St. Sever, but has never been able to determine it satisfactorily." The habit of the 

 thallus is that of some species of Stephaneplwrus of Flotow, a genus which can hardly be considered valid ; but the 

 apothecia are externally furfuraceous, not foliaceous. This species, long undescribed, occurs in Ireland (Taylor !), 

 Wales (Salwey !), Western France (Spruce ! etc.), the Canaries (Lemann ! etc.), and Madeira (Salwey !), as well as 

 in New Zealand. — C. ckloromelum, Ach., Mont. Crypt. Cub. c. ic, is perhaps too near this species. 



2. Leptogium tremettoides, Fries, Summ. Veg. Scand. p. 122. Collema tremelloides, Ach. et Auctt. 

 C. cyanescens, Schcer.! n. 409. L. azureurn, Mont.! (Collema azureum, Ach. et Auctt.). 



Hab. Abundant throughout the Islands, fertile, Colenso, etc. 



We cannot but consider L. azureum, with Eschweiler, as merely a more brilliantly coloured form of this species ; 

 it is well figured by Swartz, Lich. Amer. t. 15, and Fee, Essai, t. 2. This Lichen is almost, if not quite, a cos- 

 mopolite, the azure form belonging principally to the tropics, but occurring also in New Zealand and elsewhere. It 

 is found as far north as Sweden, and as far south as Cape Horn, and in numberless intermediate localities, but the 

 fertile state occurs principally or entirely in warmer climates. 



3. Leptogium scotinum, Fries, ut supra. Collema sinuatum, Schar.I Mium. Crit.p. 250. Iks. n. 

 405. 



Hab. Northern Island, barren, Colenso. 



The specimens agree substantially with the European form. We can scarcely, however, think this Lichen dis- 

 tinct from the very polymorphous L. lacerum, Fr. Schserer had originally united them, but in his last work he 

 considers them distinct. 0. scotinum occurs all over Europe, as far north as Lapland, and in the Canary Islands, 

 but is absent from the North American Enumeration of Tuckermann ; I suspect, however, that it occurs pretty ge- 

 nerally throughout the world. C. lacerum, at all events, occurs in the New World both within and without the 

 tropics. 



Gen. XXX. COLLEMA, Hoffm.pr.p., Fries. 



The genus Leptogium is distinguished from Collema, by Fries and others, by its proper excipulum and diapha- 

 nous thallus ; but the membranaceous division of Collema has the margin of the apothecia so nearly of the same 

 colour as the disc, that we fear no very strict limits can be drawn between them. In truth, the genera of Lichens 

 are almost ideal : in practice we have numerous instances of plants which are ambiguous between two or more 

 genera. 



1 . Collema nigrescens, Ach. et Auctt. 



"Var. ,8. leucocarpum, Bab.; apotheciis roseis pruinosis demum expallentibus.— C. leucocarpum, Tayl.! 

 Lich. Antarct. n. 144. 



Hab. Middle Island, D' Urvitte. Var. /3. Northern Island, Colenso. 



Mr. Colenso's specimens do not agree with the typical European form (i. e., a, Vesperlilio, Schser. ! Enum. Crit. 

 p. 262 ; Exs. 410), which we have not seen from New Zealand, but are to be referred to our var. leucocarpum. 

 This beautiful form has been also gathered by Mr. Gunn in Van Diemen's Land, and in Scotland by Captain 

 Carmichael. The thallus agrees with C. nigrescens, and the apothecia alone differ ; but the characters, though 

 giving the plant a striking appearance, appear to be unimportant. C. nigrescens is found all over Europe, as far 

 north as Lapland; we have it from Madeira (Salwey!), also from the United States (Greene !), where it occurs in 

 various localities (Tuckermann), and from the Himalaya Mountains (Winterbottom !), and Madras (Wight !). In 

 the south, however, it seems less frequent. 



