114 THE JounxAL of botany 



NOTES ON CORNISH PLANTS. 

 By F. Eilstoxe. 



Sisymhrivin officinale Scop. var. leiocarpnm DC. In Corn- 

 wall this is almost certainly an alien. Whilst the type is found in 

 waste ground and by roadsides in all parts of the county I have, 

 after several years' search, only been able to find this variety near 

 docks or mills, usually in company with other obvious aliens, as at 

 Par, Charlestown, and Falmouth. At Par, in the neighbourhood of 

 the docks and the Beaver Mills where aliens abound, the variety is 

 far more plentiful than the type, but one has to go onl}^ a short 

 distance inland to find the type only represented. 



Dianthus Ar)7/eri(/ L. Plants grown in a garden at Polperro have 

 behaved as biennials. Seeds collected at Hayle on Sept. 1, 1915, and 

 sown early in the following spring developed mto strong plants during 

 the summer of 1916, but no flowering shoots appeared. The severe 

 weather of the following winter did the plants no harm, and all 

 flowered al)undantly in 1917 during July, August, and September, the 

 normal flowering season. The flowers close early in tbe afternoon. 



Veronica a g rest is (agg.). Cornish forms of Veronica agresfis 

 (in the aggregate sense) present considerable difficulty. Davey's Flora 

 of Gomwall (p. 380) gives the distribution as follows : — 



V. didyma Ten. — " Not an abundant weed, bxit appears to be 



well disti'ibuted throughout the county." 

 V. agrestis L. — '• A very common and abundant weed." 



I find two forms : One — which as far as my experience goes is of 

 rare occurrence — has the pale flowers, oval sepals, gland fringed at the 

 base, and short style of V. agrestis ; but the numerous jointed hairs 

 on the stem and pedicels are not "mostly gland-tipped," as S3ane says 

 is the case with typical V. agrestis. The other — a more frequent 

 but by no means common plant — presents ditficulty chiefly in the 

 capsule being rather thickly clothed with short straight or curved 

 glandless hairs witli longer glandular hairs intermixed. Babington's 

 Itlanual speaks of the hairs on the capsule of V. agrestis as "all 

 straight and glandular" and those of V. didyma as "short dense 

 glandless hairs and otlier shorter glandular ones." Neither descrip- 

 tion fits this plant. 



The capsule clothing of the annual species of Veronica is possibly 

 an untrustworthy character ; in V. Tonrneforfii, which Syme described 

 as sparingly clothed with gland-tipped liairs, I find usually a varying 

 proportion of shorter glandless hairs intermixed, but I have noticed 

 no such variability in the agrestis foi-ms. 



Linaria Elatine Mill. On a plant of Linaria Elatine in a 

 cornfield near Polperro I found a single flower with pei-fectly regular 

 corolla similar to the peloric form of L. vulgaris. All the other 

 flowers were normal forms. 



Nitella gracilis Agardh. This pretty little plant, the occurrence 

 of which in West Cornwall was recorded in this Journal for 1912 

 (p. 348) by Messrs. Groves, appears to be a fugitive species. In the 

 ditch in which it was foimd it formed in 1911-12 a dense mass. 

 Vei'v little appeared in 1913, since when, despite careful search, I 

 have not been able to lind a trace of the plant. 



