390 
LYCOPODIACEiE. 
Quillwort, Calamaria folio hreviore et crassioref and ‘^The 
long and slender-leaved Quillwort, Calamaria folio longiore et 
graciliore and enters very clearly into their distinguishing 
characters.* The following paragraph from a letter of Linneus 
to Haller, written in 1749, and printed in Smith’s ‘ Selection of 
the Correspondence of Linnaeus, &c.”f proves that this great 
botanist considered the two forms to be species. — “ In Scania 
I have met with the flowers, male as well as female, of both 
species of Calamistrum, figured by Dillenius, in his Historia 
Muscorum^ by the name of CalamariaH'' 
Gray, in his ^Natural Arrangement of British Plants,’^ makes 
two varieties in addition to the normal form of the plant, and 
describes them as follows. 
iS. gracilis. Leaves long, slender. 
Calamaria folio longiore et graciliore. Dill. M. 541. 
y. frayilis. Leaves very brittle, slender, pointed, transparent, pores nume- 
rous, minute. 
Subularia fragilis, folio longiore et tenuiore. Rail Syn. 307, 3. 
By a reference to Pay§ it will be seen that this Subularia fra- 
gilis is an addition by Dillenius, and is probably identical with 
the Calamaria folio longiore &c. of that author ; the forms are 
thus again reduced to two, and concerning these Mr. Wilson, 
who has paid great attention to the subject, kindly sends me his 
opinion in the following words.— The solitary plants with short 
spreading leaves, I believe to be the first full development after 
the seedling state, and before any lateral extension of the rhi- 
zoma has taken place : when the plants are crowded together, 
either by lateral increase (or offsets) or by a multitude of indi- 
viduals in close contact, the fronds can grow only in an erect 
posture. In a specimen from Llyn Ogwen, the tallest I have, 
and which I cut through the middle before drying, the section 
of the rhizoma or tuber is very large, while in another specimen, 
* Calamaria folio longiore et graciliore. The long and slender-leaved 
Quillwort. A precedenti differt foliis longioribus angustioribus et rectioribus : 
radix porro durior, minus tuberosa, minusque crassa est et fibrae ejus breviores 
sunt et magis ramosee, ceeteroquin foliorum texturam, colorem, seraina et reliqua 
habet communia. — Hist. Muse. 541. 
f Linn. Corresp. ii. 433. + Nat. Air. ii. 24. § Syn. 307. 
