10 APPENDIX. 



Potamogeton pulcher Tuckerm. Spotted Pondweed. Bristol, A. F. K. Krout. 



Potamogeton Nuttallii Cham. & Sch. Nuttall's Pondweed. In streams in Trap-rock 

 region. 



Potamogeton lonchites Tuckerm. Long-leaved Pondweed. Near Sellersville. 



Potamogeton perfoliatus L. Clasping-leaved Pondweed. In ponds and streams. 



Potamogeton crispus L. Crisped Pondweed. Delaware river and Tohickon creek. 



Potamogeton foliosus Raf. Leafy Pondweed. Tohickon creek; Sellersville. 



Potamogeton pusillus L. Small Pondweed. Sellersville. 



Potamogeton diversifolius Raf. Rafmesque's Pondweed. In middle and upper dis- 

 tricts. 



Potamogeton Spirillus Tuckerm. Spiral Pondwood. Rockhill. 



Zannichellia palustris L. Horned Pondweed. Andalusia, I. C. Martindale. 



Naias flexilis (Willd.) Rost. & Schmidt. Slender Naias. Tohickon creek; Delaware 

 river; Branch creek at Sellersville. 



Naias gracillima (A. Br.) Morong. Thread-like Naias. Swamp neat Bristol. Elias 

 Diffenbaugh. 



Family 2. Alismaceae DC. 



Alisma Plantago-acquatica L. Water Plantain. Common. 



Sagittaria latifolia Willd. Broad-leaved Arrow-head. In shallow water, common. 

 Sagittaria latifolia pubescens Muhl. Hairy Arrow-head. Sellersville; Doylestown. 

 Sagittaria rigida Pursh. Sessile-Fruited Arrow-head. Sellersville; Perkasie; Bris- 

 tol, I. C. Martindale. 

 Sagittaria graminea Michx. Grass-leaved Arrow-head. Bristol, (P. B. C). 

 Sagittaria subulata (L.) Buch. Subulate Arrow-head. Bristol, I. C. Martindale. 

 Sagittaria subulata gracillima (S. Wats.) J. G. Smith. Bristol, Elias Diffenbaugh. 



Family 3. Vallisneriaceae Dumort. 



Philotria Canadensis (Michx.) Britton. Water-weed. Ponds and streams. 

 Philotria angustifolia Muhl. Narrow-leaved Water-weed. Shores of Solliday's 



island Point Pleasant, Dr. N. L. Britton. 

 Vallisneria spiralis L. Eel-grass. Tape-grass. In the Delaware. 



Order 3. GRAMINALES. 

 Family i. Gramineae Jtiss. 



Erianthus compactus Nash. Contracted Plume-grass. Andalusia, I. C. Martindale. 



Andropogon scoparius Michx. Broom Beard-grass. Sandy fields. 



Andropogon corymbosus (Chapm.) Nash. Bushy Beard-grass. Swamp, Bristol. 



Andropogon Virginicus L. Virginia Beard-grass. Quakertown; Sellersville; Bris- 

 tol; Upper Makefield, Dr. E. Newlin Williams. 



Andropogon furcatus Muhl. Forked Beard-grass. Dry soil. 



Sorghastrum avenaceum (Michx,) Nash. Indian Grass. Dry fields. 



Sorghum Halepense (L.) Pers. Johnson-grass. In the county according to 

 Dr. Porter. 



Paspalum laeve Michx. Field Paspalum. In moist fields. 



Paspalum circulare Nash. Round-flowered Paspalum. Tullytown. 



Paspalum setaceum Michx. Slender Paspalum. In the county according to Dr. 

 I. S. Moyer. 



