64 ENGLISH BOTANr. 



beneath. Ochrea} brown at the base, with about six simple nerves, 

 white and at length laciniate at the apex. Flowers in lateral fascicles 

 of 2 to 4 or rarely solitary, combined into terminal simple or branched 

 interrupted spikelike racemes leafy throughout ; the lower fascicles so 

 far separate that they scarcely form part of the spike. Pedicels erect, 

 shorter than the nut, articulated immediately below the base of the 

 perianth. Perianth coloured or subherbaceous, 5 -partite, scarcely 

 enlarged m fruit, subtruncate at the base j segments with a prominent 

 dorsal nerve. Stamens 8. Styles 3, very short, free. Nut about 

 as long as the perianth, ovate-triquetrous, striate-shagreened, dim or 

 rather dim, chestnut or brown. Plant not glandular. 



Common Knotgrass. 

 French, Ttenouee des petits oiseaxix. German, Vogel-Knoterich. 



FORM I.*— Polygonum (aviculare) agrestinum. Jord. 



P. agrestinum. Jord. Bor. Fl. du Centr. de Fr. Vol. II. p. 599. Norm. Trans. 



Tyncside Nat. Field Club, Vol. V. p. 142. 

 P. aviculare. Limi. Herb. (!). 



Stem suberect or ascending ; branches spreading-ascending or diffuse. 

 Leaves oval or elliptical-oval, subacute, about as long as the full-grown 

 internodes. Ochreas short, brown at the base, dull silvery white 

 and at length laciniate at the apex. Perianth indistinctly veined, white 

 or pale red. Nut rather shorter than the perianth, pale chestnut, dim. 

 Plant yelloAvish green. 



In corn-fields and cultivated ground. Common, and generally 

 distributed. 



England, Scotland, Ireland (?).f Annual. Late Summer, Autumn. 



Stem 9 inches to 2 feet high, stiff, the central one longer than the 

 others, and erect or ascending. Leaves 1 to 2 inches long; those at 

 the extremity of the branches rather approximate, but those on the 

 main stem, when the internodes have grown to their full length, about 

 equal to them. Flowers shortly stalked, i inch long, green, with the 



* The P. aviculare of Linnajus probably includes several subspecies ; but how many 

 of the forms described be really hereditarily distinct, we have at present no means of 

 knowing. I have not ventured, therefore, to term them subspecies, although throwing 

 them into that form. Those enumerated here were first pointed out as British by 

 the Rev. A. M. Norman in the fifth volume of the " Transactions of the Tyneside 

 Naturalists' Field Club." 



t I Jiave not seen Irish specimens, but this form is so common, in England and 

 Scotland, that it probably occurs in Ireland. 



