May 4, 1892.] 



Garden and Forest. 



207 



sures, known as the "School of Botany," ahnost everything is 

 planted in narrow parallel rows, which arrangement, although 

 not so agreeahlc to the eye as a less formal and more scat- 

 tered grouping, has the advantage of permitting perfect botan- 

 ical sequence, so that one need not constantly refer to a plan 

 in order to find particular groups of plants. In no large col- 

 lection in a limited si)ace can a classification in strict botanical 

 sequence be perfectly satisfactory, because the trees will crowd 

 and take from the soil what the neighboring smaller plants 

 should have, and it is hardly possible to give each group the 

 most congenial conditions of soil and exposure. The system 

 of labeling is very complete here, the labels being of iron, 

 neatly made, and the inscriptions in good distinct type. In- 

 deed, there are more and better labels in proportion to the 

 plants than in any scientific collection I ever saw. But, al- 

 though the labels are so numerous and in such good condi- 

 tion, their inscriptions are not always to be relied upon as 

 giving the correct name of the plant, and there is serious 

 inaccuracy in the determination of species, certainly among 

 some species from North America. To cite examples from 

 our common eastern American Oaks : Ouercus alba, Q. 

 macrocarpa and O. nigra are all represented as our Swamp 

 White Oak, Ouercus bicolor ; a Red Oak has the Scarlet 

 Oak label before it ; Ouercus alba, O. Prinus, O. prinoides, 

 Q. coccinea and other common American Oaks are not 

 represented. Betula nigra is labeled Betula lutea, and 

 the Canoe Birch (B. papyrifera) is passing as our Sweet or 

 Cherry Birch (B. leuta). A long list might be made of in- 

 stances like these, which shows that if the specimens are to 

 have their intended educational value closer attention should 

 be given to their names. Such mistakes are, no doubt, often 

 caused by tlie stupidity of workmen, but when an establish- 

 ment of such renown allows errors like these to pass unnoticed 

 it is hard to blame nurserymen or commercial dealers for dis- 

 seminating plants under wrong names. They might easily, 

 and with some justification, give as an excuse that the plants 

 were so named in the School of Botany of the Jardin des 

 Plantes at Paris. A use of synonyms is perhaps more excusa- 

 ble, and we find this and other European gardens giving us 

 credit for more species of such plants as Poplars, Ashes, Buck- 

 eyes, etc., than our botanists claim. 



The garden contains many great rarities, and those persons 

 who wish to see the most precious specimens and the very 

 latest arrivals should seek admission to the very private little 

 " pepini6re," or nursery, which is crowded with interesting 

 plants. 



The visitor comes across old trees or trees of historic in- 

 terest in various parts of the grounds of the establishment. 

 The oldest tree of Paulownia in Europe is here, having been 

 introduced in 1834, and now having a trunk six feet in circum- 

 ference. The species has been planted in some of the squares, 

 where it is kept cut back to a low broad shape, affording a 

 dense shade, and apparently bearing pruning and the city at- 

 mosphere remarkably well. In a corner near the museum 

 buildings is the aged specimen of our common Locust (Robinia 

 Pseudacacia), which, the affixed label tells us, was introduced 

 into France by Jean Robin in i5oi, and that this tree was 

 planted where it now stands by Vespasian Robin in 1636 

 (see Garden and Forest, vol. iii., p. 311). The trunk is 

 now so much decayed that the tree can hardly live much 

 longer. It has been patched up with plaster or cement, and 

 the limbs are held together by iron rods. The Cedar of 

 Lebanon planted by Bernhard de Jussieu in 1735 is apparently 

 in as good health now as it could have been at that time, and 

 it has a trunk about four feet in diameter. It is planted on a 

 dry bank, just such a situation as should be selected for it in 

 cold regions, so tliat its growth is not too rank. It seems sur- 

 prising that attempts to grow and naturalize this tree in 

 America are not more frequently made. Another plant of 

 much interest is a specimen, now thirty years old and partly 

 decayed, of the Prunus Davidiana, introduced from China by 

 the celebrated traveler and collector after whom it was named. 

 This plant has never fruited, a characteristic which has so far 

 been followed by its grafted progeny at the Arnold Arboretum, 

 where it is the very earliest of the Rose family to blossom, 

 flowering this season as early as April Sth. The flowers seem 

 perfect enough as regards stamens and pistils, and the non- 

 fruiting peculiarity has been attributed to frost or cool weather 

 at the time of blossoming, or, what may be quite as probable, 

 to the lack of pollen from flowers of different seedling plants 

 of its own kind. It is a question worth testing carefully. A 

 little-known shrub or small tree of the Witch Hazel family is 

 Parrotia Persica. A specimen of this here has several thick 

 stems from the same base, is twenty feet high, and has a 

 spread of thirty feet in diameter. It has proved quite hardy 



in the vicinity of Boston, but as its flowers are not remarkable 

 for any peculiar beauty, and it is chiefly valuable for the colors 

 of its autumnal foliage, it is perhaps no more desirable from 

 an ornamental point of view than some of our native Cornels 

 and Viburnums. The flowers appear as reddish clusters of 

 stamens in spring before the leaves. 



The garden has been the medium through which many of 

 the recently introduced Asiatic plants have been distributed, 

 and it annually issues a long list of seeds of plants it has for 

 exchange. While in some respects there are features about 

 the garden which prove a disappointment, the herbarium and 

 museum connected with it contain mines of wealth for the 

 student in botany, and everyone acquainted with the labors of 

 Franchet and other students connected with it to-day recog- 

 nizes the value of the scientific work still carried on within 

 these unpretentious walls. ^ /- <v ^ 



Arnold Arboretum. /. G. Jack. 



Internal Decay of Forest-trees. 



MY observations upon this subject, given in a recent issue 

 of Garden and Forest, have brought me a large num- 

 ber of letters from many states, showing that the evil is a 

 widespread one and difficult to account for. IVIy own limited 

 experience led me to infer that it might be due in some de- 

 gree, if not wholly, to the situation of my woodland in a deep 

 and narrow valley. I am not quite convinced that this is not 

 the fact ; but it seems evident from what I have gathered that 

 this central decay of the trunks of forest-trees is not limited to 

 such situations. Quite fortunately, in looking up another sub- 

 ject a few days since, I came upon the following, under the 

 head of " Larch," in the Allen edition of the Encyclop(sdia 

 Britannica. Here it is stated that the woolly aphis, or "Larch- 

 blight," often attacks the trees in close valleys, but rarely 

 spreads much unless other unhealthy conditions are present. 

 But " a far more formidable enemy is the disease known as the 

 'heart-rot'; it occurs in all the more advanced stages of 

 growth, occasionally attacking young Larches only ten years 

 old or less, but is more common at a later period, when the 

 trees have acquired a considerable size, sometimes spreading 

 in a short time through a whole plantation. The trees for a 

 considerable period show little sign of unhealthiness, but 

 eventually the lower part of the stem near the root begins to 

 swell somewhat, and the whole tree gradually goes off as the 

 disease advances. When cut down the trunk is found to be 

 decayed at the centre, the rot usually commencing at the 

 ground and gradually extending upward. Trees of good size 

 are thus rendered nearly worthless, often showing little sign of 

 unhealthiness until felled." The writer of this article in the 

 Encyclopedia adds that the manner in which this disease 

 spreads indicates a fungal origin, and that some fungus my- 

 celium may be the remote cause of the disease ; but that 

 "there is little doubtthatany circumstance that tends to weaken 

 the tree acts as a predisposing cause of the attack," and he 

 thinks the best safeguards are probably perfect drainage and 

 sufficient thinning. The writer of this article of the Encyclo- 

 ptcdia is C. Pierpoint Johnson, editor of Sowerby's Wild 

 Flowers. 



But the most interesting letter which has come to me in this 

 connection is from a well-known gentleman in New Hamp- 

 shire, connected with the agricultural press. From this letter 

 I make the following extracts: "I have often noticed in the 

 woods in Maine, and in other places where I have had oppor- 

 tunity, this tendency to decay at the heart, although I never 

 heard it discussed. It would seem possible that the location 

 between wet and dry soils was the cause of the trouble. We 

 know that the strip of land at the foot of a long slope, just be- 

 fore we come to a muck-swamp or a stream, is the hardest to 

 convert into tillage land. A few inches of loose black scurf 

 on a hard pan of white or rusty sand, when cleared it pro- 

 duces moss and running Blackberry-vines until Firs and Hack- 

 metacks again come to the rescue. On my farm we cleared 

 up a large meadow along a brook, and another in a dense 

 swamp where the drainage was very slow, and the trees were 

 so tall that we had to cut back some distance to get the shade 

 off the grass land. On this border the trees were rotten at the 

 heart. The White Maples and Black Ash and Elms and the 

 other trees which were at home and sound on dry land, 

 seemed to be affected on this strip. One Elm, about fifteen 

 inches in diameter, had a shell about two inches thick ; I 

 sawed it off in sections and nailed on board-bottoms for feed- 

 boxes. An Ash, with a shell about one inch thick, I split and 

 made into troughs for feeding sheep. A Yellow Birch, with 

 about three inches of shell, I made into a farm-roller." This 

 writer thinks the interior rottenness in all these trees was prob- 

 ably due to the death of the tap-roots, from the unfavorable 



