488 



Garden and Forest. 



[October 8, 1890. 



Fia;. 60. Oviparous Female. 



The orchard is bordered upon two sides by woods contain- 

 ing' many Red Cedars. It was evident that the " Neros " were 

 the most rusted upon the side of the orchard next to the 

 Cedar-trees. Two months later the leaves were nearly all off 

 of the " Nero " trees, and while the trees had set full there was 

 no fruit. The other sorts in the orchard had also suffered 

 badly from the rust, but it was later in developing- upon them. 



The Cedar-trees in the wood-lot 

 were loaded with the small, forming 

 galls, which are commonly known 

 as Cedar-apples. It looked as if a 

 bushel of these excrescences might 

 have been gathered from a single 

 tree. These galls increase in size 

 through the autumn, and in the 

 spring, when the warm rains come, 

 spores are developed and are car- 

 ried away by the winds to the young 

 Apple-leaves, where they germinate 

 and produce the rust. 



The spores produced upon the 

 Apple-leaves find their way to the 

 Cedar-leaves and there germinate 

 and produce the excrescences above 

 described. Here we have had upon 

 a grand scale, for the orchard con- 

 tains many hundreds of trees, an 

 illustration of the intimate relationship in one particular of 

 the forest and the orchard. 



The mismanagement in this case consists in permitting the 

 Cedar-trees to stand hard by the orchard, as living propagating- 

 beds of a Fungus which in one of its forms may be of serious 

 injury to the Apple-orchard. 



The relation of the Black Knot of the wild Cherry-trees to the 

 cultivated sorts is an instance similar to that of the Apple and 

 Cedar, with the difference that the Fungus runs its whole 

 course upon the same tree, and the wild Cherries simply 

 furnish a constant supply of spores to infest any cultivated 

 Cherry-tree that may be planted near by. The knots appear 

 only when spores have come from some previously in- 

 fested branch. It is a piece of folly to attempt the growing 

 of Cherries in close proximity to wild plants that are full of 

 knots. What has been said of the Cherries applies equally to 

 the Plums, for these being closely related to the Cherries are 

 attacked by the same knot-producing Fungus. If we are to 

 have clean and healthy Cherry and Plum-trees in our orchards 

 we must go through the wood-lot with the axe in search for 

 all the wild sorts that bear the Black Knot. 



The same close relationship exists between the wild Black- 

 berry and Raspberry and those under culture. The rust of 

 the one will spread to the other, and probably the same is 

 true of the Anthracnose that has been so destructive to the 

 cultivated Raspberry during the past year. 

 Rutgers College. Byron D. Halsted. 



The White Pine Louse. 



THIS insect was first described by Dr. Asa Fitch, in one of 

 his reports on the insects of New York, as Lachnus 

 Strobi. Colonies of the plant-lice are said to live upon the ends 

 of the branches of White Pine, puncturing the twigs and ex- 

 tracting the sap. and causing the bark of infested trees to have 

 a peculiar black appearance. Mention is also made of the 



Very little has since been written concerning this insect. It 

 appears to be a widely distributed species, and from its winter 

 habit it is evident that it is liable to be introduced everywhere 

 with Pine-trees from nurseries. In central Ohio it occasion- 

 ally becomes sufficiently numerous to seriously injure 

 ornamental Pines. One tree on the University campus here is 

 now almost dead because of its attack. 



Like most plant-lice, this species reproduces viviparously 

 during the summer, but on the approach of cold weather the 

 sexed individuals are produced. During October these are 

 usually the only forms present, the oviparous females being 

 congregated in great numbers upon the bark of the smaller 

 branches, with their heads nearly always directed toward 

 the trunk of the tree. When disturbed they move about 

 rapidly, usually attempting to conceal themselves on the other 

 side of the branch. At such times they also have a curious 

 habit of waving their long hind-legs in the air, probably for 

 the purpose of frightening away enemies. 



The oviparous female is represented, magnified, at Fig. 60. 

 It is about .1576 of an inch' long, shining black, more or less 

 tinged with brown, and ornamented with spots and stripes of 

 white, as represented in the illustration. The winged male is 

 also shown magnified at Fig. 61. The body is .1788 of an inch 

 long, and the wings expand about .2758 of an inch. The in- 

 sect is blackish, with a slight glaucous bloom, and a white 

 longitudinal line along the middle of the back. 



The eggs are deposited during October and November on 

 the leaflets in rows, as represented in Fig. 62 (a). Each egg is 

 .0788 of an inch long, elongato-oval, brownish when first laid, 

 but becoming' black in a short time. 



Eggs on Leaf ; 



MAGNIFIED. 



Fig. 61. Winged Male. 



fact that numbers of ants occur in company with the lice, 

 " traveling up and down the trees which they inhabit." 



One of the best remedies for this pest is kerosene emulsion. 

 There are also many natural enemies that keep it in check. 

 Ohio Experiment Station. Clarence M. Weed. 



New or Little Known Plants. 



Leucophyllum Texanum. 



LEUCOPHYLLUM is a small Mexican genus represent- 

 ing a tribe in the great family of the Figworts or 

 ScrophulariacecB. Its near relatives botanically in our 

 flora are the Mulleins, the Figworts, the Snapdragons, and 

 other familiar plants of the field and garden. The Leuco- 

 phyllums, of which three or four species are distinguished, 

 are low, intricately branched shrubs, inhabitants of the 

 desert, and distinguished by the silvery white wool which 

 covers the lower surface of the leaves, and by the large, 

 showy, axillary flowers. Two species reach the southern 

 borders of Texas, L. Texanum and L. minus. The former, 

 of which a figure appears on page 489, is a loose-growing 

 shrub of straggling habit, attaining, under favorable con- 

 ditions, a height of eight or ten feet, although it is rare to 

 find it in Texas more than half that size. There is no 

 shrub of the desert portions of the valley of the lower 

 Rio Grande more generally distributed, and certainly there 

 is not one of them which more delights the traveler in the 

 early spring months, when the large, violet-purple flowers 

 of this plant heighten the effect of its brilliant silvery 

 foliage. 



The leaves are half an inch to an inch long, obovate and 

 almost sessile, pale gray on the lower surface like the 

 shoots of the year and silvery white below. The flowers 



