THE COMMOX MAIDENHAIR FERN. 



Stqm lateral adherent to the rhizome, and as well as the raetm 9 slender, blackish purple smooth, 

 shining ; with a few scattered scales near the has© ; about as long as the fronds 



ViTimtion circinate. 



Fronds usually ovate or triangular, sometimes oblong or lanceolate, membranaceous, glabrous, 

 bright green, drooping, from six to twelve, sometimes eighteen inches in length, bipinnato or tripinnatc 

 Pinna* and Pinnule* alternate, the latter of various forms: roundish with the base truncate, 

 frub-rhomboidal, or obliquely fan-shaped, but generally more or less cuneate at the base, attached by 

 short capillary stalks ; the posterior margins entire, the superior lobate ; the sterile lobes dentate or 

 uiciso-dcntatc, the fertile obtuse or truncate, the son often occupying their entire width. 



Venation of the pinnules consisting of a series of dichotomous ramifications of the vascular bundles 

 of the petioles; the first furcation forming the extreme base of the pinnule, and the veins becoming 

 again and again forked in a Ilabclla to-radiate manner, until the whole pinnule is traversed by a series of 

 contiguous and therefore nearly parallel venules, which are disunited at their apices. In the sterile 

 ]>ortions, one of these venules is directed to each marginal tooth, in the apex of which it terminates. 

 In the fertile portions, the venules extend to the margin, and are thence continued nearly across the 

 indusium, there forming the receptacles. 



Fructification on the back of the fronds, generally distributed. Sort oblong, more or less lengthened 

 according to the width of the lobe on which they are borne, seated on the under surface of the indusium, 

 borne on the apices of all the lobes into which the anterior margin of the pinnules is divided. Indmium 

 of the same form, consisting, as it were, of a portion of the apex of the lobe, reflcxed, and changed into 

 a thin bleached veiny membrane. Spore-cases globose. Sjwres roundish or angular, ovate, smooth. 



Duration. The rhizome is perennial The fronds arc persistent* remaining until after young ones 

 are produced, if kept from being injured by frost. The young growth commences in April and May, 



The Adiautum is unlike every other British Fern ; its black, shining, slender stipes, capillary 

 ramifications, and fan-shaped pinnules, irrespective of its fructification, at once distinguish it 



The Maidenhair grows freely—in a moist close greenhouse, or in the stove, the temperature of which 

 it enjoys— in the usual light compost of turfy peat and sand, with abundant drainage. The rhizome 

 should not be buried in the soil, but fixed on the surface. The plants are injured by severe cold, even 

 when in a closed house, so that it cannot be considered a hardy Fern. Propagation is effected by 

 ili vision of the rhizomes. 



Ranging so widely over the world, it might be expected that modifications of form would occur, 

 and such indeed is the case, two or three being met with even in this country. In addition to the usual 

 state with lobed and decidedly wedge-shaped pinnules, we have, therefore, the following : — 



1 . muUifidum (W.). Dichotomous growth rarely occurs in this genus, but is occasional and inconstant. 



2. inci&um (M.). This has both the barren and fertile pinnules deeply pinnatifid, or split down into 

 long narrow lobes, but is otherwise of the usual growth* Marked examples arc rare in this country; one 

 found in Ireland by Dr. AUchin in 1853 is constant. Mr. Newman notices another from Mcwstone Bay, 

 in Devonshire. There arc, however, various gradations of this structure, both native and foreign. 



3. rotnndatum (M.>. This sub-variety, found in the Isle of Man (a very similar one also on the south- 

 west coast of England) has at first sight a different aspect. We have to thank Mr. Wilson and 

 Mr. Itylands for fronds from the Manx locality, and several correspondents have furnished the analogous 

 specimens from the English coasts. The chief peculiarity in the most marked, i>, f the Manx plant, 

 consists in the basal pinnules having a rounder outline than usual, with the base truncate ; the usual 

 cuneated base, wanting in these pinnules, appearing, however, in the upper parts of the same fronds. 

 In addition, the fronds arc narrow, and the pinmu more spreading. We cannot, however, fix the limit 

 of these peculiarities, intermediate and connecting s|>ecimens occurring from various localities. 





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