MIDDLESEX FLORA. 97 



Thuya, Toum. 



T. occidentalis, L. American Arbor-Vit^. 

 Concord, introduced by Minot Pratt. May-June. 



Chamjecyi'aris, Spach. 



C. sphaeroidea, Spach. (Cupressus thyoides, L., Man.) White 

 Cedar. 



Reading, Bedford, Natick, Hopkiiitoa, et al. Not very common. 

 May. 



JUNIPERUS, L. 



J. communis, L. Juniper. 



Common. May-June. 

 J. Virginiana, L. Red Cedar. Savin. 



Common. May. 



Taxus, Tourn. 



T. baccata, T.., var. Canadensis, Gray. 

 American Yew. Ground Hemlock. 

 Common in Ashby (L. L. Dame) ; very rare elsewhere. Apr. 



ENDOQENS. 



ARACE/E. ARUM FAMILY. 



Aris^ma, Mart. 



A. triphyllum, Torr. Indian Turnip. Jack-in-the-pulpit. 

 Common. Msly-June. 



Peltandra, Raf. 



P. undulata, Raf. (P. Virginicii, Raf., Man., in part). 

 Not uncommon. June. 



Again separated, in Engler's Monograph, from P. Virginicn, Raf. 

 The most obvious distinction is to be found in the spadix, the 

 pistillate part of which, in P. undulata, is from 1-4 to 1-5, wliile in 

 P. Virginica, it is 2-3 the length of the staminate part. All the 

 county specimens examined seem to be P. undulata. 



Calla, L. 



C. palustris, L. Water Arum. 

 Widely distributed, but not very common. May-June. 



