PRODROMUS, EXHIBENS ENUMERATIONEM PLANTARUM, QUE HACTENUS EXPLORATÆ SUNT: OR A PRODROMUS OF THE FLORA COLUMBIANA, EXHIBITING A LIST OF All the Plants WHICH HAVE AS YET BEEN COLLECTED. COMPILED BY JOHN A. BRERETON, M. D. U. S. ARMY. WASHINGTON, PRINTED BY JONATHAN ELLIOT, and soLD AT HIS STORE ON PENNSYLVANIA AVENUE. 1830 During the spring of the year 1825, after the dissolution of the late Washington Botanical Society, a few gentlemen of this city, devoted to the science of Botany, formed an association, with an earnest determination to explore and to investigate, de novo, the indigenous plants growing in the District of Columbia. The association, under the name of "The Botanic club," consisted of Wm. Mechlin, Wm. Rich, Alex'r McWilliams, M. D., the compiler, and during the following year, of James W. Robbins, M. D., but who, afterwards, in the succeeding one, removed from the District. The Prodromus, herewith submitted to the public, is, so far, the result of their investigations to the present time; and, there is no doubt, that, their contemplated Flora, will contain a much more augmented catalogue, more particularly, among the species, than is now presented. The erudite Botanist will be astonished to perceive the names of several plants, in this Prodromus, which, he is well aware belong to other localities; but when he considers the various and alpine sources of our majestic Potomac, on whose stream their rudiments are borne, and deposited along its bank, his astonishment will cease; at the Falls, too, on both sides of the river, we have never failed, at each successive excursion, to procure plants that were before unknown to us, and add the strangers to our catalogue. Among them, for the present, may be mentioned, the Dracocephalum denticulatum, Silene regia, Tillæa cymosa, Gerardia auriculata, and others. The latter is now found abundantly on the low banks of the Eastern-branch, (the Anacostia, within our limits,) and a specimen of the first was sent to Z Collins, Esq., whose tact and acumen in Botanical knowledge is unrivalled, who compared it with those of his own Herbarium, and with that of the late Rev.Dr. Muhlenberg's which now belongs to him: he fortified our decision.* This plant, as well as the Tillæa cymosa, was strictly scrutinized by Dr. Darlington, during his last attendance in the House of Representatives, whose opinion coincided with that of the club. Perhaps, also, from the abovementioned cause, may be traced in some degree, but, * See note, p. 6. more particularly, from the enthusiasm and zealous energy of the members in this delightful science, the large preponderance in the number of the Genera of the phænogamous plants, that are intended to be described in the Flora, in comparison with those of other authors on American Botany. At the end of this article a table is exhibited of the number described by each, as well as the time of their respective publications. On a reference to the table, it will not escape observation, the great disparity existing between the result of the labours of Michaux and son, with those of the late Mr. Elliott, of Charleston, S. C.: the former after exploring, during six years, the whole northern continent of America, published in Paris, their Flora Boreali-Americana; while, the states of South Carolina and Georgia, only, are the limit to the indefatigable research, and unwearied zeal of the latter, who modestly styles it a Sketch of the botany of those two states. It may not be amiss, here, to state the following singular occurrences respecting the growth of some plants noticed by one of the members, in which the rest fully concur, as appears from an extract of the |