556 



Garden and Forest. 



[Number 196. 



time I venture to name it var. Bakeri ; hills of Patzcuaro, No- 

 vember 14th, 1890. The variety may best be recognized by 

 the great size and beauty of the shaggy rhizoma. 



Polypodium plebeium, Schlecht. (3258). Shaded ledges, 

 Tamasopo Canon, September, 1890; and 3351, on trees and 

 rocks, hills of Patzcuaro, November, 1890. The two forms are 

 quite different, and both different from specimens previously 

 collected by Dr. Palmer ; but the species is apparently an ex- 

 tremely variable one, embracing many forms. 



Polypodium plumula, H. B. K. (3353). On trees and rocks, 

 hills of Patzcuaro, November, 1890. 



Polypodium sub-petiolatum, Hooker (3328). On trees and' 

 rocks, hills of Patzcuaro, November, 1890; and a somewhat 

 doubtful form (3406), not safely separable from this species, 

 was collected on the hills of Rio Hondo, August, 1890. 



Pteris cretica, L. (1985). Springy places, Sierra Madre, 

 near Monterey, June, 1888. 



Pteris longifolia, L. (3359^). Calcareousbanksand ledges, 

 Tamasopo Canon, November, 1890; and with it 3359$, var. 

 sub-bipinnata, n. var.; the latter a very remarkable torm, with 

 the lower pinnse longer than those above, piimately divided, 

 with the lower pinnules gradually reduced, as in a normal 

 frond of the species, and the apices very much prolonged. 

 Stipes and rachis stout, and especially at the base, and sur- 

 rounding the crown clothed with a coarse shatryy wool. 



Pteris quadkiaurita, R... u (341 1). Tamasopo Canon, Sep- 

 tember, 1890 



Scolopkndrium NIGRIPES, Hooker (3366). Mossy ledges, 

 Tam'as-opo Can >n, November, 1890. 



Pl.int Notes. 



Our Native Nelumbo. 



THE X luinbo of the Orient has so occupied the atten- 

 ti 11 1 the public of late years since it has become a 

 f 1 11 liar object hi many public and puvate gardens that it 

 i^, u t ti vays rem mil) r d th.it Xorih America possesses a 

 second species •. f the same genus. Less beautiful, per- 

 haps, than its Old World relative, the American Nelumbo, 

 or Water Chinquapin as it is sometimes called from a fancied 

 resemblance of its seeds to those of the true Chinquapin, is 

 one of the most interesting and striking of all hardy aqua- 

 tic plants, and there are many ponds in the eastern states 

 which might well be covered with its great circular cupped 

 leaves and pale yellow flowers raised high above the sur- 

 face of the water. 



Nelumbo lutea is by no means a rare plant in the Missis- 

 sippi basin and in many of the states which border the 

 Great Lakes. It grows sparingly in the Connecticut River 

 near Hartford and at a few other places in the east, 

 although it was probably introduced by the Indians into 

 eastern rivers, as it is so rare and local in this part of the 

 country that it does not appear probable that it grew here 

 without man's assistance. And the theory of the spread 

 of this plant beyond its natural limits by the help of the In- 

 dians is the more probable because it is known to have 

 furnished them with an important article of food in its fari- 

 naceous tubers and sweet, mealy seeds. These last are still 

 gathered in some parts of the west and north-west and 

 ground into flour. Dr. William P. C. Barton, of Philadel- 

 phia, published just seventy years ago in his fragmentary 

 " Flora of North America " a beautifully colored plate of 

 this plant, and in his description tells us that the boys 

 about Philadelphia gathered the green and succulent half- 

 ripe seed-pods from the marshy banks of the Delaware and 

 found a ready sale for them among people who considered 

 them a delicate and nutritious luxury. Perhaps some of 

 the readers of Garden and Forest can tell us whether the 

 Nelumbo is still found in Dr. Barton's station in the Dela- 

 ware, or if it has, like many other plants, been forced to 

 succumb before the march of civilization. 



Our illustration on page 557, from a photograph made by 

 Mr. D. Burnett, of Olney, Illinois, represents a pond in the 

 southern part of that state covered with the Nelumbo in 

 flower, and gives an excellent idea of how this plant ap- 

 pears on ponds and lagoons in many parts of the United 

 States. 



Foreign Correspondence. 

 London Letter. 



Iron vs. Wood in Glass Houses. — A correspondent in the 

 Gardeners' Chronicle this week raises the question, Why 

 should not iron be substituted for wood in the construction 

 of plant-houses ? There is a general objection to the use 

 of iron, because of its supposed contraction and expansion 

 under the influence of heat and cold, the condensation of 

 moisture inside and consequent production of " drip," and 

 the excessive radiation of heat from iron as compared with 

 wood. My own observation leads me to doubt whether 

 these objections really have any foundation in fact. There 

 are several large houses at Kew in which the rafters and 

 sashes are wholly iron, and neither contraction nor expan- 

 sion in them is sufficient to do any damage to the glass or 

 even to loosen it. Drip is easily prevented by a proper 

 pitch of roof, and by means of channels cast in the iron 

 rafters Radiation is not easily measured, but I do not 

 think there is any appreciable difference between the loss 

 of heat from wood and iron houses ; at any rate, the quan- 

 tity of piping for the one is the same as for the other. On 

 the other side, a great deal must be urged in favor of 

 iron as compared with wood. First cost is, of course, 

 greater ; but an iron house need not cost more than, say, 

 twice as much as wood, while it will last at least ten times 

 as long, as is proved by the old Victoria house at Kew, 

 which was built wholly of iron. Then comes the question 

 of light, and here iron is immeasurably superior to wood. 

 Sashes and rafters, if made of iron, may be so thin as 

 scarcely to obstruct any light, and yet be strong enough 

 for the largest houses and in the most exposed places. A 

 wood structure, if lightly built, soon gets out of repair and 

 is unsafe. In some gardens, famous for good cultivation, 

 I know iron houses are in favor. I will mention one — 

 that of M. Warocque, of Mariemont, near Brussels, whose 

 splendidly cultivated Cattleyas, Odontoglossums, Vandas 

 and other plants are the subject of a most eulogistic article 

 in the Gardeners' Chronicle last week by no less an author- 

 ity than Sir Trevor Laurence. The houses in which these 

 plants are grown are iron, and that they are liked is proved 

 by the fact that a new iron house for Cattleyas is about to 

 be erected. I know the stereotyped objection to the use 

 of iron for sashes and rafters, that it is bad for plants. But 

 is it ? Has any one ever proved it so ? The three essential 

 qualities in a plant-house are, I take it, durability, lightness 

 and convenience. In two of these iron is superior to wood, 

 and in the third I am inclined to think it is about equal. 



[The tendency in America is steadily toward the most 

 durable materials for greenhouses. The fear of losing heat 

 by radiation from metal is considered groundless. — Ed.] 



Effect of Fog on Plants. — The injury done to plants by 

 winter fogs in the neighborhood of large towns has recently 

 assumed quite alarming proportions. The subject has been 

 under investigation by a committee of scientific men as- 

 sisted by the Royal Society, and the first installment toward 

 a report on the whole matter was contributed in the spring 

 of this year by Dr. Oliver, of Kew. A second contribution 

 to this end was recently made by Dr. W. J. Russell, F. R. S., 

 in the form of a paper read before the Hygienic Congress, 

 and which is now published in Nature. Dr. Russell deals 

 with the whole subject of town fogs and their effects upon 

 man as well as plants. An analysis of the fog-deposit col- 

 lected from the roofs of glass houses at Kew, and which 

 had been deposited in a fortnight in February, is most in- 

 teresting. It is as follows : Carbon, 42.5 per cent; hydro- 

 carbon, 4.8 per cent; sulphuric acid, 4.0 per cent; hydro- 

 chloric acid, .8 per cent; ammonia, 1.1 per cent. ; mineral 

 matter (silica iron), 41.5 per cent; water, 5.3 per cent. 

 Total, 100.0 per cent. 



"These analyses give, I believe, for the first time a defi- 

 nite account of the composition of a fog-deposit Soot and 

 dust are by far its principal constituents, rendered sticky 

 and coherent by hydrocarbons, but I should like to give 



