till 



Garden and the Gray Herbarium, to determine doubtful specimens and to 

 investigate for me when I was not sure of the synonyms. What accuracy 

 the catalogue has in this respect is largely due to his faithful and pains- 

 taking aid. 



Dr. C. W. Swan of Boston has lengthened the list, and has also named 

 for me many puzzling grasses and sedges collected by others. It is very 

 gratifying to have the algae from a specialist of Mr. F. S. Collins's high 

 standing, and particular thanks are due him for careful mention of lo- 

 calities, and interesting notes which will not only make the list a valua- 

 ble guide to all collectors on our shores, but will frequently give begin- 

 ners a useful hint about the names of their specimens. 



Mr. John H. Redfield of Philadelphia has taken the pains to collect and 

 press specimens for me during his visits in Naiitucket, and his careful ob- 

 servations on our heaths have been of aid in confirming my own. The 

 names of other contributors will be found in the catalogue with their dis- 

 coveries. 



The Rev. Thomas Morong of Ashland, Mass, visited Nantucket in 1887, 

 and explored its ponds and runs of water as thoroughly as a two weeks' 

 stay would allow; I take much pleasure in giving this eminent botanist's 

 observations in his own words: 



"The aquatic flora of Nantucket presents several very interesting fea- 

 tures. One is the way in which some of it antagonizes the same flora on 

 the adjacent mainland. Plants which on the other side of the Sound seem 

 to be scarce, or shy in fruiting, act in an opposite fashion on the island. 

 For instance, Potamogeton pulcher, Tuckerm, and P. Oakesianus, Robbins, 

 are rather rare on the main shore, and when occurring rarely yield per- 

 fect fruit, but in many of the small ponds of Nantucket these species 

 grow literally in heaps, and bear an abundance of good fruit. The same 

 may be said of P. pectinatus, L., a form which is found in brackish water. 

 On the other hand, such species as P. perfoliatus, L. and P. pusillus, L., 

 which are extremely common and prolific on the mainland are quite scarce 

 in the Nantucket waters. 



"The same is true of Typha. The species with slender, light brown spikes, 

 known as T. angustifolia, L., is wonderfully prolific on the island, cover- 

 ing whole acres of bogs, and bearing the most luxuriant stalks, and an 

 inflorescence the spikes of which are remarkable for their variety in size 

 and shape, while the other North American species, so common in the in- 

 terior of the Northern States, T. latifolia, L., is so scarce that I had to 

 hunt for a long time before I could find any specimens. This may be 

 accounted for, perhaps, by the fact that T. angustifolia, L. loves the sea- 



