456 TRANS. OP THE ACAD. OF SCIENCE. 



quadruple)) longioribus; stigmatibus exsertis; capsula tri- 

 quetra acuminato-rostrata 1-loculari exserta; seminibus obo- 

 vatis breviter apiculatis reticulatis, areis lineolatis. — J. Muh- 

 lenbergii, Spreng. Syst. 2, 106 (1825); J. viviparus, Conrad 

 in Journ. Ac. Phil. 6, old ser. part 1, p. 105; J. Conradi, 

 Tuckerm. in Torr. Fl. N. Y. 2, 328 (1843); Gray Man. ed. 2, 

 482; Chapm. Fl. 495; J. dichotomies in herb. plur. 



Var. (3. crassicaudex, e rhizomate crasso caulibus foliisque 

 robustioribus. — J. abortivus, Chapra. Fl. 1. c. 



Var. y? subtilis, caule reptante vel fluitante radicante foli- 

 oso; foliis brevibus setaceis ex axillis proliferis ; floribus sub- 

 binis 3-andris. — J. fluitans, Michx. Fl. 1, 191 ; J. subtilis, E. 

 Mey. Syn. Luz, 31; La Harpe Mon. 135. 



From Newfoundland (ex La Harpe) and Canada, Macrae, 

 westward to Lake Superior, Robbins, and southward, chiefly 

 along the coast, to South Carolina, Curtis; var./?. in Florida, 

 Chapman', var. y. in Canada, Herb. Michaux. — A very pe- 

 culiar and, morphologically, very important plant, the synon- 

 ymy of which has been quite obscure. Meyer's original 

 diagnosis is too short, so that it permits strong doubts about 

 the identity of the plant he had in view, and his unfortunate 

 comparison of his species with J. lampocarpus and J. p>ara- 

 doxics, " enjus habitum refert" necessarily throws botanists 

 on the wrong track. But La Harpe,* who wrote only two 

 years after Meyer's publication, and who seems to have been 

 well acquainted with Meyer and with his species, gives a full 

 description which can leave no doubt, even if Meyer's herba- 

 rium did not settle the difficulty. Though originally the 

 species was described from specimens in C. Sprengel's collec- 

 tion, which seem also to have been the originals of his J. 

 Muhlenbergii (most probably received from Muhlenberg him- 

 self), several specimens, obtained later from different sources 

 (e. g. E. Tuckerman and A. Gray) are preserved in Meyer's 

 herbarium with the name of "«/". pelocarpus'''' in his own hand- 

 writing ; and others, named by him, are found in the royal 

 herbarium at Berlin. Now, this plant is so peculiar that no 

 one who has ever examined it can confound it with any other; 



* Jean de La Harpe's " Monographie des vraies Jonce'es" seems to be 

 little accessible to botanists ; it was published, 1825, in the third volume 

 of Mc'moires de la Socie'te' d' Histoire Naturelle de Paris, p. 89-181, and is 

 a work of careful research, in which I believe I can trace the conscientious 

 investigation and the critical spirit of my old and highly esteemed, now 

 departed, friend, Jacques Gay, of Paris. La Harpe was the first to give full 

 and careful descriptions of these plants and of all their organs, and only 

 after the date of his publication we find in Meyer's papers similar extended 

 accounts in place of the former short diagnoses, e. g. in the Junci of the 

 Retiquice Hankeance, published 1827. Not having been able to compare 

 Michaux's original plants, I have with confidence relied on the critical 

 references of La Harpe, especially in regard to species about which doubts 

 had existed, such as J. jiuitans, acuminutus, and polycephalus. 



