December 17, 1890.J 



Garden and Forest. 



605 



GARDEN AND FOREST, 



PUBLISHED WEEKLY BY 



THE GARDEN AND FOREST PUBLISHING CO. 



Office : Tribune Building, New York. 



Conducted by 



Professor C. S. Sargent. 



ENTERED AS SECOND CLASS HATTER AT THE POST OFFICE AT NEW YORK, N. Y. 



NEW YORK, WEDNESDAY, DECEMBER 17, 1890. 



TABLE OF CONTENTS. 



PAGE. 



Editorial Articles : — Western American Oaks. — The Lvnn Public Forest 605 



The California White Oak. (With illustration.)...'. 606 



The Autumn Flora of the Lake Michigan Pine Barrens. — II.. ..E. J. Hill. 606 

 Private Grounds and Enclosures in Cities and Towns. — II., 



Sylvester Baxter. 607 

 Plant Notes : — Vanda Batemanni and Vanda Lindeni in Their Native Country, 



Auguste Linden. 608 



New or Little Known Plants : — Streptocarpus Dunnii. (With figure.) W. 6c8 



Foreign Correspondence : — London Letter W. Watson. 610 



Cultural Department: — Rose Notes W.H. Taplin. 610 



The Calochortus in Cultivation Carl Purely . 611 



Our Twenty " Best " Apples T. H. Hoskins. 612 



The Grape Market E. Williams. 613 



Cattleya Percivaliana alba A. Dim mock. 613 



The Forest :— Value of Mountain Forests J. B. Harrison. 613 



Correspondence : — A Good Tree for the Soutli George T. King. 614 



From a Foreign Creditor Kehvay <2r> Son. 614 



A Weeping Maple Q. 614 



The Kansas Horticultural Society :— Orchards on the Prairies 5. CM. 615 



Notes 616 



Illustrations :— Streptocarpus Dunnii, half natural size, Fig'. 81 609 



A California White Oak (Qnerciis lobata) 611 



Western American Oaks. 



THE flora of western North America is rich in Oaks. 

 They form a widely scattered group of trees and 

 shrubs with many peculiar forms, very dissimilar, except 

 in the case of a few of the species, to the Oaks of the Atlantic 

 side of the continent, where the genus is also largely rep- 

 resented. The western American Oaks, especially the spe- 

 cies which inhabit the region bordering Mexico, are cer- 

 tainly the most difficult of all our trees to distinguish 

 specifically. Such characters as may be usually depended 

 on to distinguish one of our eastern Oaks from another are 

 not readily found in these western plants. Some of these 

 species, if they are regarded in any broad sense, vary with 

 latitude or soil or elevation in the most remarkable man- 

 ner, and the same plant sometimes furnishes within the 

 area of a few acres sufficient distinct forms for half a dozen 

 herbarium species, as Engelmann noticed in the case of 

 the Rocky Mountain Scrub Oak, growing on the upper 

 slopes of the Grand Canon of the Arkansas. There are spe- 

 cies which are represented in one valley by stately trees, 

 while in another, a few miles off, they are shrubs, produc- 

 ing their fruit on stems rising perhaps to a height of a foot 

 only from the ground. The leaves on one individual of a 

 species may be all entire, and on another, growing under 

 what appear to be precisely similar conditions, they may 

 be conspicuously spinosely-serrate, or the two forms may 

 be found mingled on the same plant. The fruit of different 

 individuals varies greatly, too, in size and often in shape, 

 and the botanist who studies these plants in the herbarium 

 only will find abundant material to multiply at least by ten 

 the number of the species which are now admitted by the 

 best field observers. 



The more these Oaks are studied the more difficult be- 

 comes the proper limitation of the species. But this is true 

 of nearly all genera in which many forms have been de- 

 veloped, that is, in which the tendency to seminal variation is 

 strong, as is the case, for example, with nearly all plants of the 



Rose family. All genera are difficult if one takes the trouble 

 to study them, is the true remark of a distinguished botanist 

 who has devoted thirty years of his life to the critical study 

 of the species of a single genus. That is to say, the diffi- 

 culty of defining species increases in proportion to the ex- 

 tent of our knowledge, and the more we study plants the 

 more we realize the impossibility of placing artificial limits 

 to the groups of individuals which botanists call species. 

 The study of every large genus presents difficulties enough, 

 if the attempt is made to learn everything there is to learn 

 about it; and although it is getting to be the fashion to think 

 that the labors of the systematic botanist are nearly over, 

 it is probably true that there is not a single large genus of 

 plants which is thoroughly known or understood in all its 

 aspects, and that instead of knowing the plants of the 

 world, we are only beginning to get ready to study them. 

 This is certainly true of the Oaks of western America, 

 although it is nearly a hundred years since Humboldt dis- 

 covered in Mexico one of the species which is now known 

 to grow within the present limits of the United States; and 

 although from Humboldt's day to this the botanists who 

 have dealt with the plants of western America have studied 

 the Oaks more or less intelligently. 



Thomas Nuttall, one of the best of observers, who saw 

 many of them growing in his transcontinental journeys, 

 published figures of a number of the species fifty years ago 

 in his continuation of Michaux's "North American Sylva, " 

 and there are admirable figures of some of the southern 

 species which extend into our territory from Mexico in the 

 work of the Danish botanist Liebmann on the Oaks of 

 Central America, published long after his death by his 

 compatriot, OZrsted. Dr. Albert Kellogg studied the Cali- 

 fornia Oaks for years and drew figures of many of the spe- 

 cies. Engelmann studied them long and patiently with all 

 the zeal, acumen and sound judgment which he brought to 

 the investigation of any particularly difficult group of plants. 

 The conclusions which he reached with regard to the Cali- 

 fornia Oaks are worthy of the most careful consideration, 

 although he did not have the advantage of studying these 

 trees in the field until after his mind had been pretty well 

 made up about them, and although there are several 

 species described by him which he never saw outside 

 of herbaria. When the chaotic condition of our knowl- 

 edge of the American Oaks, Pines, Firs and Junipers when 

 Engelmann began to study them, and the light which has 

 been thrown upon them by his studies, are remembered, 

 too much, certainly, cannot be said in praise of his labors 

 in this field. 



The latest study of the California Oaks has been made 

 by Professor Edward L. Greene, of the University of Cali- 

 fornia. It originated in the desire of a liberal patron of 

 science in California, Mr. James M. McDonald, to publish 

 the drawings of the Oaks left by Dr. Kellogg. They 

 were reproduced eighteen months ago, Mr. Greene sup- 

 plying the text, with descriptions of some new species 

 and many critical and valuable notes. The summer of 

 last year was then devoted by Mr. Greene to studying west- 

 ern American Oaks in many of the regions where these trees 

 occur, and now he has brought out, through the liberality 

 of Mr. McDonald, a second paper on the subject, with de- 

 scriptions and figures of several additional species and 

 varieties which the author proposes, after careful examina- 

 tions made upon living plants. 



It is not our purpose to criticise the conclusions reached 

 by Mr. Greene. He has had better opportunities than any 

 of his predecessors to observe these plants growing over 

 wide ranges of country, and therefore under dissimilar 

 conditions with regard to soil, climate and exposure, and 

 whether his ideas of the specific rank of some of the west- 

 ern Oaks are generally accepted or not, the value of his 

 investigation cannot be denied. A complete knowledge 

 of these trees, or even an approximately complete knowl- 

 edge of them, such as exists with regard to our eastern 

 Oaks, the result of two centuries of investigation, will only 

 be reached by the study of the trees in the field by a large 



