CONIFERS. 



SILVA OF NOETE AMERICA. 



5 



near the town of BriauQon in southeastern France. Formerly it 

 was used in medicine ; hut although it is still gathered bj the 

 peasants of the region, it is helieved to have disappeared from trade 

 and is no longer employed except locally. (See Fluckiger & Han- 

 bury, Pharmacographia, 373.) Melezitose, a peculiar sugar analo- 

 gous to that of the Cane, was detected in this substance by Berthelot 

 (CompL Rend, xlvii. 224). (See, also, Bonastre, Jour, de Pharm. 

 sdr. 2, xix, 443, 626. — Fliickiger & Hanbury, I. c. 373. — Bentley 

 & Trimen, Med. PI. iv. 260, t. 260.) 



^^ In North America, Larix is seriously injured by several insects, 

 but the number of species which attack these trees here and in 

 the Old World is not large. Less than fifty species of insects 

 are reported as living upon Larch-trees in North America, but it 

 is probable that the number will be much increased by a more 

 careful study of these trees in the region west of the Koeky Moun- 

 tains. The trunks of living healthy Larches do not appear to be 

 affected by borers, although several species of Scolytidse or Bark 

 Beetles of genera like Dendroctouus, Hylesinus, and Toraicus live 

 under the bark of dead, dying, or weak trees. The weakness and 

 death of these trees, which make them liable to the attacks of bor- 

 ing insects, is frequently caused by the ravages of foliage destroy- 



* ■ 



ers. The most destructive of these, which is also known in Europe, 

 is the Larch Saw-ily, Nemaius Erichsonii, Hartig, whose larvae often 

 entirely strip the trees of leaves. This pest does not appear to 

 have been much noticed in this country before 1880, but in recent 

 years it has attracted great attention on account of its abundance 

 on both native and European Larches in the northeastern states 



r 



and Canada ; and in southern Labrador, Larix Americana has been 

 almost totally destroyed by the ravages of this insect, which ap- 

 pears to be spreading northward and eastward. (See Low, Rep. 

 Geolog. Surv, Can. n. ser. viii. 36 L.) More abundant in some years 

 than others, it is nevertheless a constant menace to the successful 

 growth and development of the Larch in the region where it occurs. 

 Other species of Saw-flies which occasionally feed upon the Larch 

 are not known to be seriously injurious. 



The larvse of a minute moth known as the Larch Sack-bearer, 

 Coleophora laricella, Hiibner, which has probably been introduced 

 from Europe, have of recent years caused much injury to Larch- 

 trees in the eastern states. The bodies of these larvse are pro- 

 tected by small close-fitting cases of the same color as the bark of 

 the twigs. The larvse hibernate and in early spring eat out the 

 parenchyma of the young growing leaves, leaving on the branchlets 

 thin dry gray or whitish epidermal skeletons. In Europe, the rav- 

 ages of another small moth, Steganoptycha pinicolana, Zeller, often 

 cause great damage to Larch-trees, particularly on the high Swiss 

 Alps (Christ, Garden and Forest, viii. 238). 



I 



The Larches of western North America are sometimes injured 

 by the larv« of a butterfly, Pieris Menapia, Felder, and the larvse 

 of various moths of several families are found upon Larches, but 

 rarely in sufficient numbers to cause permanent injury. 



Among Aphids, Lachnus laricifex, Fitch, and Ckermes laricifolice, 

 Fitch, are sometimes more or less abundant on the twigs and 

 leaves ; and Larch-trees cultivated in the eastern states are occa- 

 sionally seriously affected by red mites, Tetranychus telarius, Lin- 



nseus. 



^3 The most serious disease of the Larch is a fungus, which 

 attacks the European species and is known as Canker or Krebs, 

 caused by Dasyscypha Willkommii, R. Hartig {Untersuch. Forst. 

 Bot. Institut. MuncJien. i. 63). The mature condition of this fun- 

 gus, consisting of small waxy cups, which are fringed on the outer 

 surface and margins with minute whitish hairs, while the disk is 

 yellowish red, is found in depressions on the surface of the stems 

 and young branches. It does not appear to be able to make its 

 way into the tree unless the surface of the branches has been 

 injured by hail or the attacks of insects. It is said to occur also 

 in the United States, but its range here is not well known, as Dasy- 

 scypha Willkommii of earlier authors has not always been distin- 

 guished from Dasyscypha calycina or from Dasyscypha Agassizii, 

 Berkeley & Curtis. The leaves of the European Larch are at- 

 tacked by the rust, Cceoma Laricis, Westendorp, which forms 

 golden yellow cushion-like spots on their under surface. This 



r 



fungus is believed by mycologists to be connected genetically with 

 Melampsora Tremulce, Tulasne, which forms insignificant spots on 

 the leaves of Populus tremula in Europe and occurs also on species 

 of Populus in the United States. 



A serious disease of the Larch in Germany, which causes the 



I 



leaves to fall in large quantities, is attributed by Hartig to the 

 attacks of Sphmrella laridna, K. Hartig, and the discoloration and 

 death of Larch leaves are caused by Hypodermella Laricis, Tubeuf. 

 In general, the diseases of Larix Americana do not appear to be 

 important, or at least they have not attracted the attention of 

 mycologists to any extent. Species of Polyporus and Trametes, 

 which Injure the trunks of the Tamarack, are not, however, peculiar 

 to the Larch. (See P. M. Dudley, Bull No. 1, Div. Forestry U. S. 

 Dept. Agric. Appx. 1, 52.) Polyporus officinalis, Fries, formerly 

 used in medicine, forms white irregular masses on the Larch in 

 Europe, especially in Russia. 



The diseases of the western American species of Larix have not 

 been studied. 



14 Inst. 586, t. 357. 



CONSPECTUS OF THE NORTH AMERICAN SPECIES. 



Cones small, subglobose; their scales few, longer than the bracts. 



Leaves triangular I.L.Americana. 



Cones elongated ; their scales numerous, shorter than the bracts. 



Young branchlets pubescent, soon becoming glabrous ; leaves triangular -■»....., 2. L. OCCIDENTALIS, 

 Young branchlets tomentose ; leaves tetragonal , 3. L Lyaxlh 



