66 MR. G. C. DRUCE ON THE 
On the British Species of Sea-Thrifts and Sea-Lavenders. 
By G. CrarrpcEe Drvce, M.A., F.L.S. 
[Read 6th December, 1900.] 
THE Sea-Thrift is one of our most widely distributed maritime 
plants, occurring as it does along the entire coast-line of the 
British Isles. It grows on mud-flats and on sandy and shingly 
places fronting the sea, extends up the sides of tidal rivers, and 
is even more at home on the bare rocky cliffs and islets of the 
western coast; again we meet with it on rocky cliffs, and on the 
bare stony shoulders and summits of our highest mountains. 
There is evidence to show that it is found on sea-cliffs up to 
700 feet, but few details are forthcoming as to its occurrence 
from this altitude to that of 1800 feet, although it is not un- 
likely that in the West of Scotland it may be pretty generally 
distributed through this altitudinal zone. In Durham it grows 
on Widdy-bank in Teesdale, but, so far as my experience goes, 
it is a rare plant between 1500 and 2000 teet. It is rather 
common on the cliffs of Snowdon between 2200 and 2700 feet, 
as it is on some of the Scottish mountains between 2900 and 
4000 feet. On the Great Orme’s Head it occurs at 600 feet, on 
Scawfell between 300 and 900 feet, and is common on the Irish 
mountains, between 2400 and 3400 feet. It grows at Killarney, 
where the land surface is only 90 feet above sea-level ; but in 
Ireland it is not recorded from situations more than 10 miles 
from the coast. In Somersetshire it has been seen in stony 
fields 300 feet above sea-level and as far inland as 30 miles. 
This wide altitudinal, combined as it is with an extensive 
geographical, range, and with a power of adaptability such as is 
evidenced by the extreme differences of localities, already indi- 
cated, would lead us to expect considerable variation in the 
species. That it possesses at any rate superficial differences, 
is shown by the fact that at one time or another attempts have 
been made by British botanists to establish varieties ; but whether 
from the diagnoses being faulty, or from the inconstant cha- 
racters on which these varieties have been based, or from want 
of attention being given to the subject, only one variety now 
figures in our British list, namely the var. planifolia of Syme. 
In the first edition of the ‘Manual of British Botany,’ p. 245 
(1843), Babington established a variety of Statice Armeria as 
