This section is from the book "The Native Flowers And Ferns Of The United States ", by Thomas Meehan. Also available from Amazon: The Native Flowers and Ferns of the United States in Their Botanical, Horticultural, And Popular Aspects.
Stem tufted, three to six inches in length, rigid, erect, polished, dark chestnut-brown, naked; frond four to six inches in length and two to three inches broad, deltoid, bipinnatifid; pinna rigid, spreading, one to one and a half inches in length, one-quarter to three-eighths in breadth, with numerous distantly-placed sessile pinnae on each side, which are cut to the base into three linear mucronate segments, of which the central one is the largest, but is not more than one and a half to two inches long; rachis polished like the stipe; texture coriaceous; both surfaces naked, very pale glaucous green; involucre broad, coriaceous, crenate, rolled permanently over the sori (Hooker & Baker's Synopsis Filicuni).
THOSE who are familiar with the Latin classics may re-member the pretty story told in the fifth book of Ovid's "Metamorphoses," wherein the daughters of Pierus, a wealthy Macedonian, proud of their position and of their accomplishments, challenged the Muses to a vocal contest, and for their presumption were turned into the chattering bird known as the magpie. Urania, in telling the story to Minerva, says the unfortunate girls were born in Pellsea, which is probably another name for ancient Macedonia. So many of the botanists of past times were so fond of selecting classical names for the genera they founded, that one might be pardoned for supposing that the learned German Professor Link who in 1841 first established the genus Pelloea may have had this in his mind, especially as the explanation of John Smith, in his "Historia Filicum," that the name is from a Greek word having reference to "the dusky color of the fronds," seems hardly clear, for there is no more of "dusky" color in the fronds of Pellaea than in many other ferns. But it so happens that in this case Link tells us what botanists do not always tell, his reason for the name "stipes rigidus, badius," "from whence I have given it the name of Pellaa - badius being the Latin adjective denoting a chestnut-bay or sorrel color;" and, as we see, from the stipes or stalks, and not "from the fronds." The color of the stalks of a fern would not, of course, do to build a genus on, but the polished brown stipes, as we see in our plate of Pellaa ornithopus, is so common to many of the genus that it was a good thought to take this character for the little important meaning of a family name. Previous to Link's time the species of this genus were classed with Pteris, a well-known family of Ferns, and from which, indeed, they differ so little in the characters usually adopted for genera, that Professor Wood, in one of the editions of his "Class-Book of Botany," might seem justified in remarking that "their separation to a new genus is an over-refinement." It is, however, a case where the general appearance suggests a difference which science has not been able clearly to define. For instance, Chapman, in the " Flora of the Southern United States," describes Pteris as a genus having "sporangia borne on a transverse marginal receptacle connecting the ends of the veins," while Pellaa is described as having "fruit dots oblong or linear at the ends of the veins, confluent in a broad marginal line of fructification;" but the student will understand that he has a Pellaa much more readily from the general appearance of the plant than by the nice distinctions this nearly synonymous language conveys. Mr. John Smith well remarks that the "normal punctiform sori (that is, the fruit dots) of some species of Pellaa are so united as scarcely to differ in technical character from Pteris." Then there are other genera, such as Allosorus and Cheilanthes, from which it is often difficult to distinguish some species of Pellaa.
Plants of the genus Pteris are known as "Brake" or "Bracken," and under this name especially the Pteris aquilina is known in English poetry, as well as in popular English literature gener-allv. The use of this word in connection with this class of ferns comes from very ancient times, and is believed to be derived from an ancient Saxon word similar to it, and having the same meaning as we attach to a "clearing," or land ready or capable of being broken up with the plough, as distinguished from woodland; and then from the "Brake Fern." generally growing in these open places rather than in woods, as most other ferns of the old world known to the ancients did. Pellaa, taken from Pteris, grows rather on rocky places, and it is probable from this, in connection with the ancient popular name, that it has received the popular name of "Rock-Brake." "Bird's-foot" is the translation of its specific name, ornithopus. The lower pinnules are ternately divided, and have much the appearance of a track made by a bird's foot, from whence the name is derived. The student must not, however, consider this division of the pinnae a very important character, as it is not unusual to see specimens in which most of the pinnae are undivided, and when better opportunities for investigation are afforded, many of the western species now thought to be distinct will probably be found united under fewer names.
This species is a very pretty one. It is a native of California, from whence it often comes in collections of dried specimens, showing that it is not uncommon in that region. As already noted of Pellaa in general, it does not make its home in low alluvial soils where rains and floods would soon tear its delicate fronds away; but it loves, in the language of the poet Percival, to exhibit "------its rare and beautiful forms,
In sporting amid those towers of stone, And is safe, when the wrathful spirit of storms
Has made the top of the wave his own."
Dr. C. C. Parry, however, informed the writer of this that in his collections in California he often found it on gravelly knolls, where it could be protected from washing away by the aid of such plants as Adenostoma, Ceanothus, or Paonia Brownii, when the fronds would be very luxuriant though then assuming a rather stiff habit, and having a real lurid hue, warranting Mr. John Smith's interpretation of the generic name.
It varies very much in size: sometimes plants fruiting perfectly are but a few inches high. We have some fronds before us, sent by Dr. L. D. Morse from San Mateo, which are nearly a foot in length. This specimen has very few ternate pinnules. Our illustration is a good average size, and was taken from a plant growing in the Arnold Arboretum, under Mr. Jackson Dawson's care.
It is now not uncommon under culture, and proves itself well adapted to window gardening, not being so particular about a moist atmosphere as many cultivated ferns are.
1. An average-sized plant with pinnules nearly all entire, only a few being ternate.
2. An enlarged pair of pinnules, showing the broad indusium extending all along the margin of the frond.