MIDDLESEX FLOEA. 



N. STLVESTKE, R. Br. Yellow Cress. 

 Mediord, 1887 (P. S. Collins) ; Newton (C. J. Sprague; Man. 1859). 

 May-June. Nat. from Eu. 



N. palustre, DC. Maesh Ceess. 

 Somerville, Cambridge, Framingham, Groton, et al. Eather com- 

 mon. May-July. 



N. Akmoeacia, Fries. Hoeseeadish. 

 Often found escaped from cultivation. Apparently persistent. 

 May-June. Nat. from Eu. 



N. amphibium, E. Br. var. auriculatum, Eeich. 

 Cambridge, rubbish-heap, 1884 (Walter Deane ; specimen in herb, 

 of). Adv. from Eu. 



"Pod elliptical or oblong, three or four times shorter than the 

 pedicel ; immersed leaves undivided, lanceolate, attenuate at both 

 ends, sessile ; upper leaves 'pectinato-pinnatifid or lyrate ; petals 

 longer than the calyx; var. auriculatum, DC. Leaves furnished 

 with small auricles at the base." Koch, Syn. Flor. Germ. 



Dentaeia, L. Peppee-eoot. 



D. diphylla, Michx. 



Arlington (E. Tuckerman) ; Belmont, specimen in the Boott herb. 



May. 

 J), heterophylla, Nutt. 



Lowell (Albert S. Guild; W. P. Atwood). Eare. Apr.-May. 



Adv. from the South. 



* D. laciniata, Muhl. 



Belmont, near Eailroad Station (Wm. Boott) . Apr.-May. 



CAED AMINE, L. 



C. rhomboidea, DC. White Speing-Ceess. 

 Medford and Belmont (F. S. Collins) ; Woburn (C. E. Perkins) ; 

 Framingham (Eev. J. H. Temple) ; et al. May. 



* C.jixpmboldiea., DC, var. purpurea, Torr. Pueple Speing- 

 Ceess. 



Arlington, May 8, 1865 (Wm. Boott). 

 C. hirsuta, L. Small Bittee-Ceess. 



Common. May-June. 

 C. hirsuta, L., var. sylvatica, Gray. 



Melrose and Medford (F. S. Collins). May-June. 



Aeabis, L. 



A. hirsuta, Scop. Haiet Eock-Ceess. 

 SomervUle (C. E. Perkins) ; June-July. 



