540 COLLEMACEAE. 



1. PHYSMA Mass. 

 1. Physma umbella (Tuck.) Riddle. 



Omphalaria umbella Tuck, apud Nyl. Syn. Lich. 1: 105. 1858. 



On a rock, New Providence, at sink-hole, on Farringdon Road : Alabama. 



2. COLLEMA Hill. 



Surface of thallus granulose. 1. C. rupestre. 

 Thallus not granulose. 



Thallus radiately nlicate, with rounded lobes. 2. C. nigrescens. 



Thallus merely uneven, with narrow lobes. 3. C. laciniatum. 



1. Collema rupestre (Sw.) Kabenh. Deutsch. Krypt. Flora 2: 50. 1845. 



Lichen rupestris Sw. Meth. Muscor. 37. 1781. 



Lichen flaccidus Ach. Nov. Act. Acad. Sci. Stockholm 5: 14, pi. 1, f. 4. 



1795. 

 Collema flaccidum Ach. Lich. Univ. 647. 1810. 



On Annona glabra, Cat Island, at Port Howe : widely distributed in temperate 

 regions of both hemispheres. 



2. Collema nigrescens (Huds.) Ach. Syn. Lich. 321. 1814. 



Lichen nigrescens Huds. Fl. Angl. 450. 1762. 



On trees, Great Bahama, at Barnett's Point, and New Providence, at Waterloo 

 Coppice : cosmopolitan.. 



The material is without isidia, and would represent what Wainio (Lich. Bres. 

 1: 235. 1890) calls Collema vespertilio (Lightf.) Wainio, but the original plants 

 upon which these names were based are doubtful. 



3. Collema laciniatum Nyl. Syn. Lich. 1 : 115. 1858. 



At base of tree, Watling's Island, near Cockburn Town : Alabama ; Kansas. 

 The type came from calcareous rocks, and as the present material is sterile, the de- 

 termination must be considered uncertain, although the thalline characters agree 

 with the material in the Tuckerman Herbarium. 



3. LEPTOGIUM S. F. Gray. 



/ 



Thallus dark green to black. 1. L. chloromelum. 

 Thallus bluish lead-color. 



Thalline margin of apothecia a plaited corona. 2. L. bullatum. 



Thalline margin of apothecia thickly lobulate. 3. L. phyllocarpum. 



1. Leptogium chloromelum (Sw.) Nyl. Syn. Lich. 1: 128. 1858. 



Lichen chloromelos Sw. Fl. Ind. Occ. 3 : 1892. 1806. 



On trees, New Providence, Watling's Island, and Salt Key Bank, Anguilla 

 Islands : throughout North America, and recorded as cosmopolitan. 



This is the most " Collema-ttke " of all the species of Leptogium, and is very 

 variable. Some of the specimens cited are near the variety stellans Tuck. Syn. N. A. 

 Lich. 1 : 163. 1882. 



2. Leptogium bullatum (Ach.) Nyl. Syn. Lich. 1: 129. 1858. 



Lichen bullatus Ach. Lich. Suec. Prodr. 137. 1798. 



On trees, Great Bahama, at Golden Grove, and New Providence, along Soldier's 

 Road : widely distributed in tropical America, and recorded from tropical Asia and 

 New Zealand. 



3. Leptogium phyllocarpum (Pers.) Nyl. Syn. Lich. 1: 130. 1858. 



Collema phyllocarpum Pers. in Gaudich. Voy. Uran. 204. 1826. 

 Leptogium bullatum var. phyllocarpum Tuck. Syn. N. A. Lich. 1: 165. 



1882. 



On trees, New Providence, at Grantstown and along Soldier's Road : widely dis- 

 tributed in tropical regions of both hemispheres. 



