139 



The fronds of this species of Lastraea grow in a circle from the 

 crown of the caudex, and attain from one to four or five feet in height, 

 the base of the stipes being densely covered with pale-coloured, 

 chaffy scales, of various sizes : they are sub-bipinnate, broadly lan- 

 ceolate, often oblong-abrupt, with an acuminated apex. The pinnae 

 are linear-lanceolate, acute, alternate, the lowest shorter than those 

 about the middle of the frond ; they are pinnate next the main rachis, 

 the pinnules having a narrow attachment, but being scarcely stalked; 

 in the rest of the pinnae the pinnules are usually more or less com- 

 bined at the base, most so in the variety abbreviata, but less so in 

 the variety incisa, than in the normal state, in which latter the pin- 

 nules and lobes are of an oblong obtuse outline, ci en ato- serrate on 

 the margin, and more acutely and closely serrate at the apex. In 

 the variety incisa the pinnae are somewhat more distinctly pinnate, 

 and they are also more elongate, and narrow at the point, the mar- 

 gins being more or less deeply incised or lobed, each of the lobes 

 having from two to four or five serratures. The midvein of the pin- 

 nules and lobes is sinuous ; the lateral veins are alternate, and they 

 become branched near the midvein — in the normal plant usually 

 simply forked, or occasionally with the posterior branch again forked ; 

 the anterior branch on a greater or less number of these lateral veins 

 at the base of the pinnule bears a sorus just beyond the fork, so that 

 the sori in this case form a short line on each side of and near the 

 midvein, extending about half the length of the pinnule. In the va- 

 riety incisa the lateral veins are more compound, being sometimes 

 three- sometimes four- and at the base usually many-branched; but 

 the sori, as far as I have observed, are only produced on the anterior 

 branch, as in the more common plant, so that they are also ranged in 

 a line on each side the midvein ; they extend, however, from the base 

 nearly to the apex of the pinnule. In the variety abbreviata, on the 

 other hand, the sori are confined to the base of the obsolete pinnules, 

 forming a line against the rachis of the pinnae. The sori are covered 

 by smooth, very persistent, reniform indusia, each of which is con- 

 nected to the back of the vein by the sinus, which is turned away 

 from the apex of the pinnule or lobe. 



April, 1848. 



Thomas Moore. 



