ILOKA Ol-' THE EAST KIOING OF YORKSHIRE. 191 



AROIDE.^. 



1563. Arum maculatum. Linn., 84. 



(Spotted Arum. " Lords and Ladies," " Bulls and Cows," 



"Parson in Pulpit," Holderness, and certain other 



ver}- unsavoury names). 



Native, Eng., 1-7. May, IL 



Verv common in woods and hedgerows in all the divisiont^^. 



1565. Acorus Calamus. Linn., 31. 



(Sweet flag). 



Native, Eng., 3. June, III. 



Rare in localities; the old ponds at Risby, near Beverley 

 (R.T.). It still grows here abundantly but flowers only 

 sparingly, 1898*; near Kirkham Abbey (M.B.S.). 



LEMNACE^. 



1566. Lemna trisulca. Linn., 73. 



(Ivy-leaved Duckweed). 



Native, Eng., 1-7. July, I. 



Very common in stagnant dykes, especially in Holder- 

 ness. All four species of Lemna may frequently be found 

 growing together and flowering near Howden and on Skipwith 

 Common (W.N.C.). 



1567. L. minor. Linn., io6. 

 (Lesser Duckweed). 



Native, Brit., i, 7. July, I. 



Very common. 



1568. L. gibba. Linn., 53. 



Native, Eng., 1-7. July, I. 



Frequent. Ditches near Beverley (B.) and Hull.* Meaux 

 Abbev,"^ Hornsea Mere, and Preston. 



