320 



Garden and Forest. 



[July 2, 1890. 



Bacteria were found present, but no attempts were made to 

 determine the bacterial origin of the disease. 



But small bodies were found within the substance of the 

 smaller roots and these at once suggested undeveloped worms 

 of minute size called nematodes. As the search continued 

 the mature worms were found in full activity. 



Readers of Garden and Forest will remember an article on 

 the Clematis disease, by Professor Comstock, which appeared 

 in the number for January 29th of this year. In this article 

 Professor Comstock showed that these minute worms, which 

 are akin to the well known " vinegar eel," a minute creature 

 often seen wriggling near the surface of vinegar, were the 

 cause of this wide-spread disease of the Clematis. In a note 

 of mine on Professor Comstock's paper, which appeared in 

 the number for February 5th, it was stated that a part at least 

 of the Violet-disease was due to a similar cause, and I men- 

 tioned the fact that Dr. Neal, of the Florida Experiment Station, 

 and Professor Atkinson, of the Alabama Station, had each is- 

 sued large illustrated bulletins which show the ravages of these 

 thread-worms in the Peach and Orange-groves of the south. 

 A species of these nematodes is said to cause the so-called 

 tulip-root in Oats in England. 



These worms are very destructive to some of our principal 

 garden crops, and it is evident that a large field is opening in 

 this country for the labors of the econorhic helminthologist. 

 Unfortunately no cheap method has been discovered which 

 can entirely defeat the attacks of the nematodes. One plan is 

 to cultivate upon an infested area only such crops as are not 

 attacked by these worms, so that they can be starved out, or if 

 the rotation of crops is practiced unsusceptible plants may be 

 used in some part of the rotation. As some weeds, the Pig- 

 weed for example, furnish particularly favorable shelter for 

 these microscopic enemies, they should be kept scrupulously 

 subdued by clean culture. 



Nematodes may be introduced into a field in composts and 

 barnyard manure, and therefore it is wise, in case of a threat- 

 ened invasion, to use unslaked lime in thin layers when con- 

 structing the compost or manure pile. 



It will be noted that the two bulletins spoken of are from the 

 far south. With us in the latitude of New York there is much 

 less occasion for alarm in an ordinary season, for the cold of 

 an average winter is too severe for these worms to withstand. 

 The large numbers of nematodes that have been found upon 

 various crops, such as Spinach and Violets, during the past 

 winter, is probably due to weather unusually favorable to 

 them. A winter warm enough to give us Peach-blossoms 

 during almost every week from December to March was well 

 suited to their rapid multiplication. 



Corn is the only member of the Grass family mentioned in 

 the printed lists of hosts for nematodes. The Oat, therefore, 

 is an additional species in that family that is subject to these 

 titteicks 

 Rutgers College. Byron D. Halsted. 



New or Little Known Plants. 



Trillium sessile, var. Californicum. 



THE genus Trillium contains several attractive garden- 

 plants. Trillium grandiflorum, the large, white- 

 flowered species of the eastern and northern states, is the 

 most beautiful. of them, and when once established in a 

 suitable position it is not excelled in beauty by any spring- 

 flowering herb. The Painted Trillium, as Trillium erythro- 

 carpum is called on account of the bright purple-rose 

 colored markings which appear on the lower part of the 

 petals, is hardly less beautiful, although the flowers are 

 considerably smaller and much more modest than those of 

 the better known species which we have referred to above. 



Another plant of this genus, of first-rate value as a gar- 

 den-plant, has been brought into cultivation in recent 

 years. It is the Pacific coast form of a widely distributed 

 eastern species, Trillium sessile, found from Pennsylvania 

 and Wisconsin to Florida and Alabama. The western form 

 of this plant, known as variety Californicum, is widely dis- 

 tributed through the northern part of California west of the 

 Sierra Nevada and extends into Oregon. The habit of the 

 plant and the character of the flower is represented in our 

 figure on page 321, which is made from a specimen grown 

 in the garden of Gillett & Horsford, of South wick, Massa- 

 chusetts, who have obligingly sent it to us for the purpose. 



Trillium sessile, var. Californicum, is a stout plant 



with broadly rhombic-ovate leaves varying from three to 

 six inches in length, lanceolate, acute, erect sepals, and 

 oblong or rhombic-obovate petals, which vary in length 

 from one to four inches. These differ in color on different 

 plants from purple to pure white and at first are nearly up- 

 right, becoming reflexed above the middle when the flower 

 is fully expanded. The form with pure white petals is the 

 handsomest and most desirable as a garden-plant. 



The Pacific coast Trillium, like the other species of the 

 genus, is most satisfactory when it is planted in deep, 

 moist soil in the shade of deciduous trees ; that is, where it 

 can enjoy early in the season or during the blooming 

 period full exposure to the light, and where later it can be 

 protected by the leaves of the overhanging trees from the 

 full blaze of the sun. Trilliums should be planted early in 

 the autumn or not later than the first of October if good 

 flowers are expected from them the following spring. They 

 do not show, however, what they are really capable of 

 until they have been allowed to grow undisturbed in the 

 same spot during three or four years and have become 

 well established. Then, if the soil in which they are 

 planted suits them and the situation is a favorable one, 

 they form broad masses of immense leaves and produce 

 flowers of large size and surprising beauty. 



Foreign Correspondence. 



London Letter. — Paeonies. 



AMONG the many beautiful border plants that have sprung 

 into popularity in England in recent years, the Paeonies 

 take foremost rank. Like the Daffodils, they were favorite 

 garden plants in England over three hundred years ago. 

 Gerard said of them in 1580, " All sorts of Paeonies do grow in 

 our London gardens." The revival of a love for these and 

 many other old-fashioned hardy plants may be traced to the 

 development of out-door gardening and especially of the 

 mixed border. Paeonies are essentially border-plants. They 

 are hardy, easy to cultivate, almost any soil agreeing with 

 them; they live to a good age and they flower freely. Their 

 flowers are enormous, often elegant and fragrant, whilst their 

 colors vary from deep purple-crimson to almost white. What 

 could one desire more in a hardy border-plant ? In England, 

 Belgium and France nurserymen have done much during the 

 last twenty years to improve the flowers in form and color and 

 also to increase the number of good varieties. A collection 

 of Paeonies is now a feature in all good gardens in June, 

 whereas a few years ago they found admirers chiefly among 

 the cottager. One of the principal raisers and growers of 

 these plants in England, Mr. Kelway, of Langport, admits that. 

 he was first impressed with the beauties and capabilities of 

 Paeonies on seeing them worn by the men and women assem- 

 bled at an Irish wake some thirty years ago. Some of the best 

 of the sorts he has bred from, he obtained from an old woman 

 in his parish. The long lost P. Whitmanniana, a yellow flowered 

 species, was rediscovered about eight years ago in an obscure 

 Irish garden. Messrs. Barr & Son, George Paul, Ware and 

 Kelway now possess an immense stock of Paeonies, an indica- 

 tion of their popularity in England. With a view to focusing 

 the Paeony-knowledge and material, the Royal Horticultural 

 Society has this week held a special exhibition of the plants, 

 and papers on their culture, history and classification were read 

 by Mr. George Paul and Mr. Lynch, of the Cambridge Botanic 

 Gardens. The exhibits were marvelous in point of size, color 

 and fragrance in the flowers, Messrs. Kelway staging a splen- 

 did array of blooms. Some of the new sorts received certifi- 

 cates. Whilst such beautiful double-flowered kinds as Princess 

 Mary, Sainfoin, James Kelway and Lady L. Brumwell were 

 greatly admired, the single flowered varieties received much 

 attention. Some of them were remarkable for great substance 

 of petal, far in advance of the older kinds, in which flimsiness 

 of flower was a drawback. A deep blood-crimson kind 

 named Stanley, a pink and white called Dorothy Tennant, and 

 Julia Kelway, a blush white, were amongst the most notable 

 of the single flowered sorts. 



Tree Paeonies were not well represented, most of them being 

 past flower here. The behavior of the Tree or Moutan Paeony 

 in English gardens is not always satisfactory. In some situa- 

 tions the plants die a foot for every six inches they grow ; in 

 others they grow well for a time, and then go off suddenly, 

 apparently attacked by some fungoid disease ; whilst in some 



