Smooth except some bristly-chaffy hairs on the midribs and especially on the dark purple and polished stalk and rachis, six to fifteen inches high; frond coriaceous, pale, once or below twice pinnate; the divisions broadly linear or oblong, or the sterile sometimes oval, chiefly entire, somewhat heart-shaped or else truncate at the stalked base; veins about twice forked. Root-stocks short and stout: stipes clustered. (Gray's Manual of the Botany of the Northern United States. See also Chapman's Flora of the Southern United States, Wood's Class-Book of Botany, and Williamson's Ferns of Kentucky.)

Dark Purple Rock Brake Pellaea Atropurpurea Link N 20012

Pellaea Atropurpurea

POETS generally sing of ferns in connection with the deep recesses of gloomy forests; with low clamp situations; or if with more elevated places, they are where " The mist hovers over the fountain and rill, And curls in light folds on the slope of the hill."

Whenever the fern is mentioned it is usually when shaded ravines or flowery dells are to be adorned; when the poet strays near some sprayey fountain; or where trickling rills course through some quiet mead. Percival, whose lines we have quoted above, in another place is describing Greece from Mount Helicon; and, addressing one of the streams, sings:

" Then be my guide, Wandering Termessus, upward through thy vale, And let me find, beneath the twisted boughs Of these old evergreens, coolness and shade, To make my toil the easier. Darkly rolls Thy current under them, and hollower sounds Thy hidden roar. I just can catch a glimpse Of yon deep pool, dark and mysterious, Sunk in its well of rock; and now from out A tuft of seeded fern I see thee plunge, Tinted with golden green, for there a sunbeam Strays through thy arch of shade."

This pretty sketch would have been tame indeed without the help of the "seeded fern," which, by the aid of the straggling sunbeam, gave the golden green to the waters and at the same time the chief central point to the poet's picture. Most of us have pleasant remembrances of sylvan scenes, in which some graceful fern has taken what we might almost term a loving part. But all ferns are not like these. There are some which, if we may borrow a Shakespearian image of human things, are so delicately nurtured that they are only fitted to " Caper nimbly in a lady's chamber, To the lascivious pleading of a lute," while there are others again who rather delight in " Mounting barbed steeds, To fright the souls of fearful adversaries."

Our present species, Pellaa atropurpurea, is one of these brave courageous species. It does not grow in the rich soil of shaded woods, or seek the advantages of cooling streams; but boldly takes to the clefts of exposed rocks, or covers with its blue-green fronds the faces of dry and ruined walls. In such situations it often grows with a luxuriance truly surprising. Soon after the termination of the civil war, the writer was collecting plants among the smoked ruins of Harper's Ferry in Virginia, and these were covered with this fern, often with fronds ten inches long. Indeed it seems to prefer to associate itself with mortar, and the mural works of man. The abutments of the bridges across the Susquehanna river at Harrisburg were formerly covered with it, and may probably be so clothed still. In a wild condition it seems to prefer limestone rocks, though it is by no means confined to them. It grows luxuriantly in the soapstone quarries on the Schuylkill river above Philadelphia. Other observers have noted that it does well elsewhere than on limestone. In the first volume of the " Botanical Gazette," Dr. J. Schenck says that it grows on a bare sandstone cliff in the lower Wabash valley of Indiana, "though it is usually thought to be found only on calcareous rock;" and in the same magazine Mr. H. E. Copeland says of some locations in Wisconsin: "It grows as thrifty on the sandstone as when growing on calcareous rocks in the southern part of the State." That the prevalent opinion is erroneous is further confirmed by Mr. Williamson, who in his " Ferns of Kentucky " remarks that " it is well distributed over the State wherever there are limestone cliffs, though it is occasionally found in sandstone formations."

It is interesting to notice how the knowledge of its geography has progressed. It was known to Linnaeus as Pteris atropurpu-rea, having been probably made known to Europeans by Clayton, to whom it seemed so rare that he wrote to Gronovius that he found it in " a shady place among the roots of red cedars at Point-look-out, on the Rappahannock." This was previous to the year 1739. Michaux in the early part of the present century gave it a wider range by the expression, " Rocks in the Alle-ghanies." Beck in 1833 widened its range "from New York to Carolina." In Sir John Franklin's voyage to the Arctic seas in 1819-22, it was found in these high regions, though it did not attain there more than an inch or two in height. It has since been found by Lyell in Greenland; and, though it is not found continuously, but in isolated spots, it has a wide geographical range accorded to few other American Ferns. How nice it is in its isolation may be gathered from a remark of Dr. Coulter in the first volume of the "Botanical Gazette," who is describing it as it grows near Hanover, in Indiana. He says: "The apparent choice in the range of heights is very marked in the case of Pellaa atropurpurea, which is confined to a range on the topmost rocks, little if at all exceeding thirty feet in vertical height." From various sources we have accounts of its being found in Texas, New Mexico, Arkansas, Colorado, and all through the Rocky Mountains to arctic America. It does not seem to be common on the seaboard. So far as we know, it has not been found in New Jersey, nor further northeast than Vermont.

The taxonomial history of our plant, or that which relates to its classification, has been a very chequered one. Linnaeus, as we have seen, refers to it as Pteris atropurpurea, and this will be found in use by the earlier of our modern botanists. In the earlier editions of his " Manual " Dr. Gray has it an Allosorus, which he abandons in the later ones; while Thomas Moore, a noted English authority on Ferns, says in "The Treasury of Botany" that all those Pellaas which are not true Pteris "should be referred to Platyloma." After all it must be admitted that there is very little difference between some of the genera of Ferns. For instance, some would make Pellaa atropurpurea an Allosorus because the leaves have a thick leathery texture, and because the veins are not very apparent. But when the frond is held against the light, the venation is distinctly seen, as in our Fig. 3.

As a fern for cultivation, it has not appeared often as a success; but this is chiefly owing to a want of care in growing it. Though satisfied with harsh conditions in a state of nature, it demands a little petting before it willingly enters the service of man. Though Paxton says it was introduced to English culture in 1770, it still seems rare even in that land of good gardeners. A note in the volume of the "Gardener's Magazine" for 1879 says: "This pretty fern is found from arctic America to the Andes, where it grows at the height of from 8,000 to 10,000 feet. It is very rare in the country, and these notes were made from specimens in the Royal Gardens at Kew, where the plant does well. It should be placed in a well-drained position in the limestone, and a plentiful portion of sand and limestone must be added to the peat in which it is planted."

Our drawing was made from a specimen grown by Mr. Jackson Dawson, the fruiting portion, Fig. 3, being from our own (Virginia specimens.

Explanations Of The Plate

1. Plant with young growth.

2. Barren frond from last year.

3. Portion of a fertile frond, showing the sporangia with their indusium along the edge.