160 LEPTOGIUM. 



Tuckerman Gen. 1872. Oregon, Hall. British Columbia, Z/#aW; 



Macoun. A similar lichen but infertile was found in the 



Organ Mountains, Texas, Wright, but the species is unknown to 



us except on the West Coast. The plant varies, from wider 



states (8 mm - wide in the larger, and 2 mm - in the narrower parts) 

 with something of the aspect of L. lacerum, a, as figured in 

 Schser. Enum. t. 10, f. 2, to much narrowed, suffruticulose ones, 

 with the colour and whole appearance of conditions of Cetraria 

 aculeata. 



13. L. Apalachense (Tuckerm.) Nyl.; thallus of middling 

 size, stellate, multifid ; brownish-olivaceous ; the narrow, radi- 

 ant, imbricated divisions mostly convex and branch-like, with 

 obtuse tips, delicately rugulose ; beneath paler and a little chan- 

 nelled; apothecia small, scattered, or in botryoid clusters, 

 innate -sessile, from zeorine becoming biatorine ; the rufous disk 

 at length flat, the paler margin entire. Spores ellipsoid, from 



4-locular becoming sub-muriform, decolorate, j^ mic. Nyl. 



Syn. l,p. 133. Collema, Tuckerm. Suppl. 2, I. c.'p. 200. 



Calcareous rocks. Alabama (Peters), Tuckerman I. c. 1859. 

 Georgia, Eavenel. Missouri, Hall. 



14. L. crenatellum, Tuckerm.; thallus effuse, from squami- 

 form soon dilated and imbricate-lobate ; glaucous-cinerascent 

 and lurid; the small, ascendant, smooth lobes with wavy and 

 crenate edges; apothecia small, zeorine, sessile; the reddish 

 disk finally tumid, and the thin, crenulate, thalline margin dis- 

 appearing. Spores always in fours in the thekes, ovoid- ellip- 

 soid, from 4-locular becoming sub-muriform, decolorate, ^ mic. 

 Suppl. 2, I. c.p. 201. 



At the base of trunks of White Ash in swamps, Vermont 

 (Frost), Tuckerman I. c. 1859. Base of button-bushes (Cepha- 

 lanthus) in pond-holes, Illinois, Hall. 



15. L. pulchellum (Ach.) Nyl.; thallus middling-sized, rosu- 

 late, round-lobed ; from glaucous-green becoming lead- coloured 

 and lurid; the entire lobes plicate - papulose and delicately 

 wrinkled above, paler and deeply pitted and also wrinkled be- 

 neath; apothecia middling-sized, lecanorine, sub-pedicellate; 

 the flattish, brown disk at length excluding the thin and smooth 

 or finally plicate -rugose, thalline margin. Spores ovoid-ellip- 

 soid, sub-muriform (thte transverse series of spore-cells oftener 



