414 Muhlenbergia, Volume 2 



Euphorbia GLYPTOSPERMAEngelm. i. Ridge-seeded spurge 

 In sandy soil and on sand banks, Willamette river, University 

 Park. etc. June to September. Apetalous. 



X Euphorbia peploides Gouan. i. On ballast grounds 

 and waste places, Lower Albina, etc. Adventive from Europe. 

 June to September. Apetalous. 



X Euphorbia Heuoscopia L. i. Wartweed. Ballast 

 grounds and waste places, Lower Albina, East Portland, etc. 

 Adventive from Europe. May to September. Apetalous. 



Euphorbia crenulata Engelm. 2-4. Tcothed spurge. 

 On Rock island, Willamette river opposite Elk Rock and at Wil- 

 lamette falls. Rare here. May to September. Apetalous. 



Piscaria Piper. 



Piscaria setigera (Hook.) Piper, i. Turkey mullein. 

 {Eremocarpus setigerus.) On ballast grounds and along rail- 

 road tracks, Lower Albina and East Portland. Native of eastern 

 Oregon and California; adventive here. May to July. Flowers 

 small, apetalous. 



CALLITRICHACEAE Lindl. Water starwort Family. 

 Calutriche L. Water starwort. 

 Calutriche verna L. 4. Vernal water starwort. Ponds 

 aad ditches, East Portland. June to August. Minute, apetalous. 



LIMNANTHACEAE Lindl. False mermaid Family. 



Floerkea Willd. False mermaid 

 Floerkea proserpinacoides Willd. I. False mermaid. 

 Under ash trees, head of Sauvie's island. April to June. White. 



ANACARDIACEAE Lindl. Sumac Family. 

 Rhus L. Sumac. 

 Rhus diversiloba T. &. G. Poison oak. Very common 

 in open woods and on sunny slopes, Macleay Park, Fulton, South 

 Portland, Mt. Tabor, Rocky Butte, Brooklyn, Slavin road, Cor- 

 nell road, St. Helens road, 21st and Pettygrove streets, 22d and 

 Thurman streets, etc. Vile, noxious shrub, without a single re- 

 deeming quality or beauty, either of flower, fruit or leaf. The 

 clearing away of the forest in this section during the past forty 



