fronds, less elongated and slighter in the barren ; smooth, rounded
behind, channelled in front, the base ebony-ooloured, pale grceii
upwards ; lateral, and adherent to tbe caudex. Rachis also smooth
and ohannollod iu front, tbe secondary raohides bearing a few small
scattered scales, and loose spreading deciduous hairs ; similar hairs
also appear hero and there on tbe veins beneatb, and along tbe
margins of tbe lobes.
Fronds from six or eight inches to four feet in height, including
tbe stipes, and from about four to ton inches in breadth, lanceolate
or oblong-lanoeolate, scarcely narrowed below, delicate green,
membranaceous, erect, pinnate ; the barren ones having apparently
broader leafy segments, while those of tbo fertile fronds
seem to be narrower and more acute, owing to the rolling in of
tbe margin over or towards tbe sori. Pinnæ numerous, subopposite
or alternate, spreading, linoar-lanceolate, deeply pinnatifid.
Segments oblong, obtuse or sometimes acute, straight or falcate,
entire or slightly sinuate-lobed ; tbo basal ones, especially those on
tbe anterior side, often longer than, and quite distinct from, the
rest. The fertile fronds differ from tbe sterile ones in having tbe
margins of their segments rcvolute, and in being taller, with
stouter stipites.
Venation of tbe lobes consisting of a stout costa or midvein,
flexuous in tbe upper part, from which proceed alternate once or
twice forked veins, tbe venules running out to the margin. Tbe
veins become forked very soon after leaving tbe midvein.
Fructification on tbe back of the frond, occupying tbe whole
under surface in tbe fertile fronds. Soi'i small, round, situated
near the base of tbe venules, i. e., just above tbo fork of the vein,
and forming a line on each side tbe midvein, and about equally
distant from it and tbe margin, though apparently marginal from
the involution of tbe edge of the frond ; they are at first distmct,
but often become laterally confluent, and sometimes effused over
tbe wbole of the small space between tbe roUed-up margins.
Indusium a small deboate roundish-reniform membrane, attached
by its posterior edge, the free margin lacerate and glandular.
Spore-cases numerous, brown, obovate. Spores oblong or reniform,
strongly murioated.
Duration. The caudex is perennial. The fronds are only of
annual duration ; tbe barren ones grow up about May, tbe fertile
in July, all being destroyed by tho frosts of autumn.
This plant may be distinguished from tbe other British species of
Lastrea by its habit alone, its long, comparatively slender, creeping
caudex being unlike th a t of any other native species; but notwithstanding
this, and the fact tbat its fronds are really quite
unlike those of L . montana {Oreopteris), tbe species bas not nnfre-
quently been confounded Yvith tbat plant. I t will be found to
differ from it in having the long creeping caudex just referred to,
whilst L . montana bas a short thick tufted caudex, merely decumbent
in habit. I t differs further, in having its fronds of tbeir full
width almost to tbe very base, and supported by a long bare stipes,
whilst L . montana bas diminishing pinnæ carried down almost to
tbe base of the stipes ; and moreover, in having fronds which are
almost free from glands, whilst those of L. montana are very
conspicuously resinose-glandular on tbo under surface, and very
fragrant. I t is still less like any other British species of Lastrea.
Lastrea Thelypteris is easily cultivated, merely requiring a light
boggy soil, and abundant moisture. Out of doors it should therefore
have a damp border, or should be planted in some wettisb place
about the fernery. A boggy pool at the foot of a mass of rook-work,
where it might be accompanied by Osmunda, would be a congenial
position. In pots, it must have a very abundant supply of water ;
and tbe vessels in which it is planted, should be large and shallow,
so that its long caudices may have space to spread naturally over
the surface of the soil. Peaty soil, alone, or mixed witb a proportion
of decaying leaves and light sandy loam, will be congenial to it.
I t is increased readily by division of the caudex.
Though widely dispersed in tbe United Kingdom, tbe Marsh
Fern is a comparatively rare plant, being local in its occurrence, and
growing only in marshy and boggy situations, from some of wbicb
it is certainly being displaced by drainage. I t is, however, generally
abundant where present. In England it is spread from tbe southern