76 BULLETIN OF THE 



(very distinct from the type) and Ceonothus ovatus : also Ranun- 

 culus pusillus and Utricularia gibba. But rich and varied as are 

 these lower flats, they are excelled by High Island, the flora of 

 which is by far the most exuberant of all within the knowledge of 

 botanists. Here we find Jeffersonia diphylla, Caulophyllum thalic- 

 troides, Erigenia bulbosa, Silene nivea, Valeriana paucifiora, Ery- 

 thronium albidum, Iris cristata, and a great number of others of our 

 most highly prized plants, many of which are found nowhere else. 



Above the feeder is a series of islands in the river lying for the 

 most part near the Maryland shore, and to which the maps, so far 

 as I can learn, assign no names. The first of these lies well out in 

 the river, and has been made to form a part of the feeder-dam. It 

 is low and frequently overflowed, and has not, as yet, furnished 

 many rare plants, though here Arabis dentata and some others have 

 been found. It has been designated Feeder-dam Island. .The 

 second is half or three-quarters of a mile above, lies higher, and is 

 covered with a very dense and luxuriant herbaceous vegetation and 

 fine trees, chiefly of Box Elder, Negundo aceroides, from which cir- 

 cumstance and the peculiar impression which the long gracefully 

 pendent staminate flower of these trees produced on the occasion of 

 its first discovery by a botanical party it received the name of Box 

 Elder Island. The third island is a short distance above the last, 

 has a more elevated central portion and a similar vegetation. 

 Here was found, on our first visit, and also on subsequent ones, 

 Delphinium tricome, and for this contribution to the Flora Colum- 

 biana it was christened Larkspur Island. The fourth of these 

 islands is, in many respects, similar to the two last described, and 

 upon it stands the only indigenous specimen of Acer saccharinum 

 yet found here. It has, therefore, been appropriately named Sugar- 

 maple Island. Erythronium albidum, Trillium sessile, Jeffersonia 

 diphylla and similar species abound on all these islands, while on 

 the Larkspur Island, besides the Delphinium, has also been found 

 Phacelia Purshii. The beauty of these natural flower-gardens in 

 the months of April and May is unequaled in my experience. The 

 light and rich alluvial soil causes the vegetation to shoot up with 

 magic rapidity at the first genial rays of the vernal sun, and often 

 the harbinger of spring, Erigenia bulbosa, true to its name, will 

 greet the delighted rambler in late February or early March. 



The opposite, or Virginia side of the Upper Potomac, consists 

 entirely of bold bluffs, interrupted by deep ravines, often contain- 



