MIDDLESEX FLORA. 



N. SYLVESTRE, R. Br. YELLOW CrESS. 



Medford, 1887 (F. S. Collins) ; Newton (C. J. Sprague ; Man. 1859). 

 May-June. Nat. from Eu. 



N. palustre, DC. Marsh Cress. 

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

 mon. May-July. 



N. Armoracia, Fries. Horseradish. 

 Often found escaped from cultivation. Apparently persistent. 

 May- June. Nat. from Eu. 



JV. amphihium , R. Br. var. auriculatum, Reich. 

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

 of) . Adv. from Eu. 



"Pod elliptical or oblong, three or four times slaorter 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, Sjm. Flor. Germ. 



Dentaria, L. Pepper-root, 



D. diphylla, Michx. 



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



May. 

 D. heterophylla, Nutt. 



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



Adv. from the South. 



* D. laciniata, Muhl. 



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



Cardamine, L. 



C. rhomboidea, DC. White Spring-Cress. 

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

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



* C. rhomboidea, DC, var. purpurea, Torr. Purple Spring- 

 Cress. 



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

 C. hirsuta, L, Small Bitter-Cress. 



Common. May-June. 

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



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



Arabis, L. 



A. hirsuta, Scop. Hairy Rock-Cress. 

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



