n8 



Garden and Forest. 



[Number 474. 



here set on the ground level, and thus appear to good advan- 

 tage. This appears to be the best season to bring them into 

 flower, for I have noticed when they have been held in check 

 in cool houses to retard the flowering season they have not 

 done so well. Mr. Harris, gardener to Mr. H. H. Hunnewell, 

 tells me when they have been advanced in cool houses to the 

 bud stage, and are then taken into warmer quarters to bloom, 

 they expand to almost twice the si/.e they would be if grown 

 continuously cool. Mr. Sanders, gardener for Professor Sar- 

 gent, is an enthusiast in growing Begonias. A selected seed- 

 ling from B. insignis shows up remarkably well in this large 

 collection, and compared with the type is far more ornamental. 

 A handsome plant of B. Ferdinand de Lesseps, a shrubby 

 greenhouse hybrid, has made wonderful growth. It is a 

 summer bloomer, and later will be a mass of white flowers. 

 Streptocarpus Wendlandii is just coming into bloom here. 

 Like some of the older varieties, it produces only a single leaf, 

 but of very large size. The leaf itself is not without beauty, 

 and, reflexing, gives the plant a peculiar one-sided appearance. 

 The flowers, however, are neither as large nor as handsome 

 as one would expect, and are, in fact, smaller than those of the 

 newer hybrids. The Cherokee Roses, already in bloom, give 

 promise of hundreds of flowers each day in the near future. 

 The large single white flowers are really handsome, and it is 

 surprising that such a lovely Rose is not more generally 

 grown as a cool-house climber in the north. Some of the 

 retail florists have tried it, but it does not seem to satisfy the 

 popular taste, which prefers double flowers. Some new 

 hybrid Hippeastrums, recently imported, look promising in 

 one of the houses, and some are already in bloom. The 

 elimination of the green band is nearly complete, and shows 

 what careful hybridization can accomplish. A pan of the 

 while Grape Hyacinth, Muscari botryoides, var. alba, was per- 

 fection itself. These less common bulbs grown in this way 

 are very effective. In the grounds I noted one of the original 

 plants of Berberis Thunbergii, now a bush about nine feet in 

 diameter and five feet high, and about fifteen years old. It is 

 in excellent health and shows its value for permanent plant- 

 ing. 



At Dr. Weld's place I found a fine collection of stove tropical 

 plants. That handsome, but deadly, Aroid, Dieffenbachia, is 

 here represented by several handsome plants. This native of 

 tropical South America is valuable on account of its luxuriantly 

 spotted foliage. Among the most highly ornamental plants 

 seen here is Heliconia aurea striata, with large Maranta-like 

 foliage, striped and spotted with yellow. It is allied to the 

 Banana family. Licuala grandis, a rare and beautiful Palm 

 from the South Sea Islands, makes a beautiful display here. 

 Until it was recently rediscovered in limited numbers, the 

 large plant in the collection of Mr. H. H. Hunnewell was one 

 of only four or five known in cultivation. The beauty of its 

 almost circular and purely palmate leaves is not approached 

 by any species of the entire Palm family. Pavetta Borbonica 

 is a beautiful foliage plant of slow growth, and resembles a 

 dark green spotted Ficus, with opposite leaves. It is allied to 

 the Ixora. Other plants noted in Dr. Weld's houses were 

 specimens of Dracaena gracilis, a distinct and beautiful species 

 with long, narrow, recurving foliage, slightly tinted with pur- 

 ple. Its value lies in its distinctness. Cypripediums are 

 among the few greenhouse Orchids with handsome foliage. 

 They are here represented by some beautiful pans of C. Law- 

 renceanum and C. callosum, besides a varied general collec- 

 tion. Curmeria (Homalomena) Wallisii, a noteworthy plant, 

 looked like a dwarf Dieffenbachia, but on close inspection we 

 find the leaves are leathery, its stems are different, and it is of 

 much slower growth and difficult to cultivate. A splendid 

 show of Cinerarias and Cyclamens makes one house bright 

 with color, while some standard plants of Acacia pubescens 

 and A. heterophylla serve to relieve what would otherwise be 

 a surfeiting impression, for some of these gorgeous displays 

 seem almost too showy. Among the Cyclamens are such 

 good varieties as Rosy Morn, Alba magnifica, Mont Blanc and 

 Brilliant. 



Wellesley, Mass T. D. Hatfield. 



The Rotation of Species of Trees Under Forest 

 Conditions. 



To the Editor of Garden and Forest : 



Sir, — Considerable discussion has been occasioned by the 

 questions in regard to reforestation in the first report of the 

 Chief Fire Warden of Minnesota. This problem of forest per- 

 petuation and forest rotation is an interesting study. The 

 opinion often stated is that the natural rotation in species of 



forest trees is a necessary result of an impoverished condition 

 of the soil ; that one species or family takes a different food 

 from another, and after one species has taken the nutriment 

 it prefers there is not enough food remaining for a second 

 crop, so that another kind steps in, a kind that relishes and 

 thrives upon the plant-food that remains. But this idea of soil 

 impoverishment under natural forest conditions is in opposition 

 to all modern teaching. It is held, nowadays, that the forest 

 is a restorer of plant-food, so that one crop of trees leaves the 

 soil better for having sustained it. Forest rotation or the suc- 

 cession of species is not, therefore, sustained by the theory of 

 deficient nourishment. Even if we were to specialize and 

 attribute the phenomenon to a single ingredient of plant-food, 

 the hypothesis would still be inadequate, for all classes of 

 forest trees take the same foods in slightly varying propor- 

 tions only. 



But if variation in the condition of the soil does not serve 

 the purpose, will a consideration of the tree's reproductive 

 organs solve the problem ? The Pine family is capable of pro- 

 ducing, and frequently does produce, an abundant seed crop. 

 Failure to reproduce itself cannot then be attributed to lack 

 of seed-production. Are these seeds prepared to withstand 

 adverse conditions ? No, they have no hard nutty covering 

 as do those of the Oaks and Hickories. The seed, while pro- 

 vided with wings to facilitate its transportation, soon loses its 

 vitality if exposed even to the conditions of the natural forest. 

 In other words, the Pine seed must find congenial surround- 

 ings for germination soon after it is shed from the cone, or it 

 perishes. Pines do not produce seed each year in succession, 

 and consequently the loss of the seed crop of one season may 

 delay a stand of young seedlings for several years. Young 

 seedlings of most trees are tender as regards adverse sur- 

 roundings, and this is especially true of the Pine. When favor- 

 ably lodged, however, the seeds of the Pine germinate readily 

 and the young seedlings thrive under proper conditions of 

 shade and the like, but with our lack of system in torest man- 

 agement these congenial conditions for germinating the seed 

 and developing the young seedlings are rarely provided. When 

 a propitious environment chances to be present, the White 

 Pine reproduces itself readily. 



Since, then, other species are more commonly the successors 

 of the Pine than its own kind, it stands to reason that the con- 

 ditions have been too severe for the reproduction of the Pine. 

 It is also an indication that other species are more virile than 

 the Pine. Is there in nature any reason for this? If the 

 theory of a natural progression from the lower to higher 

 forms in the organic world is to be maintained^, there is ample 

 reason for these peculiarities of rotation or succession of 

 species. 



According to Gray, the Pines are the oldest representatives 

 of our forest flora. The giant Sequoia is a lone survivor of a 

 great, and at one time numerous, group of plants. The 

 Gingko, a native of the orient, is at present reduced to the 

 stand of a monotype species. Formerly it undoubtedly had 

 many coordinates. The Sequoia, the Ginkgo and the Pines 

 all belong to the same general scattered family of Coniferce. 

 It is known that there are among this family representatives of 

 once prosperous genera. What does this mean ? Simply 

 this, that the great order Conifene is slowly and gradually losing 

 ground in the natural competition for supremacy. They are, 

 in other words, less virile than many of their competitors. 

 More congenial conditions for growth and development must 

 be provided for them than for other species with which they 

 now have to contend. Then, again, if we examine the struc- 

 ture of the floral or reproductive apparatus of the Pine we find 

 it less highly developed than the same organs in their more 

 successful rivals. This indicates that the Pine is less highly 

 organized than other trees. The more highly a plant or 

 animal is organized, or the more complex its differentiation, 

 the more capable it becomes of adapting itself to slightly 

 changed conditions. The low position in the scale occupied 

 by the Pine, to an extent, explains why it does not reproduce 

 itself. In fact this, to my mind, is the keynote to the whole 

 situation, for all necessary adaptive variations are limited by 

 the station occupied by the plant. 



If what has been stated is true, and the White Pine requires 

 extra care in order to induce it to perpetuate itself, then it is 

 our business as lumbermen and foresters to study those con- 

 ditions and plan to conduct our operations so as to maintain 

 the proper soil, shade, moisture and otherconditions suited to 

 the growth of this most valuable forest-tree. 



Substitutions for this timber are constantly being tried, but 

 for some purposes the White Pine is greatly preferred to other 

 woods, and it will always be in demand. 



West Virginia University, Morgantown, W. Va. L. C. Corbett. 



