MICHIGAN ACADEMY OF SCIENCE. 139 



Equisetaceae. Horsetail Family. 



Equisetum arvense L. Common Horsetail. — Very common, especially in 

 sandy ground, on roadsides and along railways. A good sand binder, 



Equisetum pratense Ehrh. Thicket Horsetail. — Reported by Prof. John 

 Macoun as found near Sarnia, Ont. Apparently rare. 



Equisetum sylvaticum L. Wood Horsetail. — Common in damp open woods 

 and thickets. 



Equisetum fluviatile L. Swamp Horsetail. Pipes. — Common in swamps, 

 ditches, shalloAv water, on borders of ponds and slow streams. 



Equisetum hyemale intermedium A. A. Eaton. Scouring Rush. — Com- 

 mon in dry and sandy ground. At first mistaken for E. laevigatum, A. Br. 



Equisetum hyemale affine (Engelm.) A. A. Eaton. Smaller Scouring 

 Rush. — On railroad embankment near Blackwell Station. 



Equisetum hyemale robustum (A. Br.) A. A. Eaton. (E. nobustum A. Br.) 

 Large Scouring Rush. — Occasional in damp sandy ground. Abundant 

 along the G. T. Railway near Blackwell Station. 



Equisetum variegatum Schleich. Variegated Equisetum. — Abundant in 

 several places at Port Franks in wet ground. 



Equisetum variegatum jesupi A. A. Eaton. Smaller Variegated Equi- 

 setum. — Occasional on drj^ or damp sandy ground. 



Equisetum scirpoides Michx. Sedge-like Equisetum. — Occasional in 

 moist shaded places. Abundant at Rock Glen. A plant easily overlooked. 



Lycopodiaceae. Club Moss Family. 



Lycopodium lucidulum Michx. Shining Club Moss. — Frequent in cool 

 damp woods. 



Lycopodium annotinum L. Stiff Club-moss. Pine woods near Port Franks 

 Occasional. 



Lycopodium clavatum L. Common Club-moss. Dry woods. Frequent. 



Lycopodium obscurum dendroideum D. C, Eaton. Ground Pine. — Oc- 

 casional in dry woods. 



Lycopodium complanatum L. Trailing Christmas Green. — Occasional in 

 woods and thickets, more common in pine woods near Port Franks. 



Selaginellaceae. Selaginella Family. 



Selaginella apus (L.) Spreng. Creeping Selaginella. — Frequent in damp 

 open places. 



Isoetaceae. Quill wort Family. 



Isoetes macrospora Dur. Lake Quillwort. Abundant in the mouths of 

 St. Clair River. 



Taxaceae. Yew Family. 



Taxus canadensis Marsh. American Yew. Ground Hemlock. — Occa- 

 sional in damp woods and thickets; frequent among pines near Port Franks. 



Pinaceae. Pine Family. 



Pinus strobus L. White Pine. — Occasional south of Lake Huron shore, 

 and other parts of the county. Frequent at Port Franks. Formerly abun- 

 dant near Thedford in sandy spots. At present few large trees left. 



