460 



GARDENERS' MAGAZINE. 



Wild 



Dartvin took great pains to investigate these minute flowers. On opening 

 them he found the petals rudimentary or absent, the pollen grains 

 actually growing in the anthers, the pistil small, and the stigma, or 

 pollen deposit point, much reduced. Fertilisation so conducted was a 

 sure and speedy process, and but few pollen grains, only one hundred, 

 were needed to effect it in the flower. As the violet produces seeds 

 chiefly from these self-fertilised flowers, it is somewhat difficult to explain 

 the use of the showy ones. Their persistence can only be accounted for 

 by the use such flowers are in securing an occasional cross by insect 

 visits. The blue colour is said to be specially attractive to bees, as 



shown by Sir John 

 Relation to Insects." - - * 



This point is disputed by recent papers of Professor Plateau, who, 

 from personal observation, concludes that insects are but little affected 

 by colour ; what they seek is pollen or nectar, and to these they are 

 guided with certainty by the sense of smell rather than that of sight. 

 Sir John Lubbock replied to these memoirs at a meeting of the 

 Linna?an Society, refuting the conclusions of Professor Plateau by the 

 record of experiments of his own, and maintaining that the conclusions 

 of Sprengel and Darwin are in no wise weakened by these new observa- 

 tions. To the unconscious selection of insects he still considered we 

 were indebted for the beauty of our gardens and the sweetness of our 

 fields. In the violet, the nodding flower, the dry pollen, the thin, curved 

 style, and the overlapping stamen ends seem all adapted for such a 

 purpose. Such was the opinion of Sprengel after his study of the violets 

 of his day, an opinion which was set aside for seventy years and then 

 brought out again to demonstrate with Darwin "how actual forces were 

 operating before our eyes to modify living forms." 



A letter I have received from the curator of the Cambridge Botanic 

 Gardens states the matter well. " The genus viola is one of great 

 botanical interest. It gives us the opportunity of showing that evolution 

 takes place under our very eyes." To return to the question of colour. 

 The blue shade is due to a substance known as anthocyanin. It is 

 remarkable for its constancy in the violet and pansy, none of the culti- 

 vated varieties as yet being without a trace in the spur. Anthocyanin 

 appears to be necessary for the protection of plant food substances from 

 the action of light. If a root of violet be placed in water it develops a 

 violet tinge in the light. The reddish-violet tints of sprouting shoots in 

 spring, and the autumn tints of leaves are also caused by the same agent 

 when performing its useful function of protecting certain foods in transit. 



With regard to the evolution of colour in violets, Miiller states, "that 

 facts go to show they were originally yellow." The smallest and most 

 short spurred is V. biflora. It is visited by flies and short-lipped bees, 

 and its flowers are yellow. The smallest form of V. tricolor has whitish- 

 yellow flowers. Many alpine violas show all stages from yellow to blue, 

 some are yellow throughout ; in others the flowers are yellow when open 

 and change gradually to blue as they fade ; in others the change is a 

 quicker one. The most highly specialised form is V. calcarata. This is 

 almost always blue, but reverts occasionally to the ancestral yellow. It 

 is fertilised only by lepidoptera; one, a quick worker, has been seen to visit 

 one hundred and ninety-four flowers in six and three-quarter minutes. 



The perfume of violets is also found in the wallflower, stock, hesperis, 

 gentian, daphne, and blue water lily. The effect of the colour and odour 

 is seen in the fact that the large, brightly-coloured but scentless pansy is 

 piuch less visited than the small, blue, sweet-scented violet. V. cornuta 

 is adapted for night fertilisation by moths by its long spur and evening 

 perfume. 



Much of the perfume sold as that of the violet, until recently, was 

 obtained from the Florentine iris. The discovery of ionone, the artificial 

 essence of violets, is both a scientific and commercial success. The dis- 

 persal of the violet seeds is caused by the action of the capsule after 



open ol three boat-shaped valves, each con- 

 taining a double row of seeds. These valves in curling exert such 

 pressure upon the seeds as to shoot them out to a considerable distance. 



The cultivation of the violet is a most important business, winter 

 blooming violets being grown in the ODen. and then lifted for 

 protection in frames by thousands. The 



open, 



j — ~-~v^. x 1 1 use of runners, helping the 



violet to form new plants at a distance from the parent, but affecting 

 considerably its flowering capacity, is an important detail in this con- 

 nection. The finest of the sweet violets or violas are mostly of French 

 origin. Princess of Wales is one of the finest of these, having very 

 Iar-e blue single flowers, strongly scented, and long, thick stalks. A few 

 American violets, such as California, have been sent out, and are among 

 the newest and finest additions. Easy as it is to find the common 

 violets at this season, the large and beautiful new-fashioned violets 



made such a sensation at our autumn show, may tairly now be 

 difficult to obtain. One large firm of growers write from Devon : "Your 

 date, April 6th, is far too late for violet blooms to be characteristic, or 

 tit to be seen." Good advice I received was "keep the violets as cool as 

 possible. I certainly kept them cool, but not collected. 



have to thank Messrs. Barr for beautiful specimens 

 1 nncess of Wales and Viola pedata. The others, I was assured by one 



1 



of 



WORK FOR THE WEEK. 



WARM 



Cattleya Mossi^e will have finished flowering so th* • 

 and the plants be placed in their growing quarters mUSt a, , so delude 



necessary, and a slight watering until active growth £k~*5 m ° re shude » ill £ 

 where plants have been repotted earlier in the season tk' exce P l in cases 

 imported plants of this cattleya will be fairly brisk bv thi. «„ 5" root ^wi of 

 removed, and the plants placed in toim), ™^ „_j ... ' ° tne crocks must k. 



>f the 

 may be 



basket* • 



bulbous stem ; fresh material will be beneficial and in , g at the te 

 necessary to shake out the plants, give them new materiK ^ " 

 the species thrives well in flat pans suspended from the roof in th*™* V r 

 C. Schilleriana may be treated exactly in the same manner C PU . eya houS€ - 

 ties may also require attention in this direction, and a shadv'nl^ 1 - ° andvarie - 

 house is suitable for it at all times. C. GaskeluW ^l^Sl^L^ 

 display in the cattleya houses, filling up a blank between rtH k,n S a n «* 

 autumn and winter flowerings. The flowers are very tVentih^V * nd lhe 

 become spotted unless kept in a dry place. C. suoerba will nVT u amp > ^ 

 its beautiful flowers ; it is, unfortunately, a ve Jdiffi^, " "k° W * l )rod "ciag 



alpine specialist, could only be obtained by an enthusiast. Viola 



vfl' \- calcarata, V. striata, V. Munbyana, and V. cornuta, 

 were supplied bv Messrs Uoxui ■ ,tn ..i.... * ' :j u- _ _ ' 



in pans or baskets suspended from the roof. Epidendrum bicornntnm £ ng L W 

 difficult plant to grow successfully, but the present is a good time to re W^" 

 top-dress it as necessary. Many growers find the dendrobium house a vervTuitln' 

 place for this species while growing ; others find the cattleya house suitable and 

 whichever way is found to be the most successful it should certainly be continued 

 The new leaves on Phaktnopis will be growing freely, so it will be well to 

 avoid a stagnant atmosphere ; keep the bottom ventilators open at all times 

 unless cold winds are blowing ; pay strict attention to shading. Dendrobium 

 Wardianum and D. crassinode will be now well advanced in growth, so a littl 

 stimulant, such as guano, used alternately with liquid cow manure, should be given 

 in a very weak state for a beginning, increasing it gradually as the growths finish 

 The evergreen dendrobiums will mostly be growing vigorously, so plenty of water 

 will be required, and the syringe must be used pretty freely ; fumigating must be 

 done occasionally to keep down red spider or thrips. Selenepediums will require 

 to be carefully watered, and do not allow water to lodge in the axils of the leaves • 

 a slight syringing is, however, necessary at this time of the year. Cypripediums 

 in the warm house will require plenty of water and a good moist atmosphere ; 

 fumigation at the present season is most important among this class, for yellow 

 thrips attacks them, and is a great enemy. If it has obtained a footing in any 

 collection, it is a good plan to dust the leaves where attacked with tobacco 

 powder,^ leaving the same on until the thrips are thoroughly eradicated, after 

 which give them a good sponging with soapy water or fir-tree oil insecticide used 

 a little weaker than the directions given on the bottle. — T. Stafford, Tyntes- 

 field Gardens. 



CONSERVATORY AND GREENHOUSE. 



At last we appear likely to have a continuation of summer weather, and the 

 plantsman's labour will increase, for not only will he have to take care that planti 

 growing in small pots do not suffer for even a short period for the want of water 

 at the roots ; but syringing, which perhaps has only been necessary once a day, 

 must be performed twice and copiously. Moreover, there will be many winter- 

 (lowering plants, including those used for forcing, such as thorns, roses, lilacs, 

 and many other things which require most generous treatment through the heat of 

 summer, if they are to flower freely during the short dull days of winter, when 

 their blossoms are so valued. It is not uncommon to find these standing about in 

 odd corners, and what watering is afforded is done in a rough way and at long 

 intervals sometimes, causing them to lose their foliage prematurely. It is much 

 better to arrange all such plants in a group, standing the tallest in the centre in 

 such a way that watering is done easily. If the pots can be plunged in a l>ed of 

 ashes so much the better, or, failing this, a few inches of decayed straw or leaves 

 placed between them will assist to keep the roots cool and active during a period 

 of drought. A free syringing overhead after a hot day will also prove beneficial to 

 these and other plants whose roots are restricted. Those who grow a large collec- 

 tion of chrysanthemums know the extra labour incurred in watering and syringing 

 when the weather remains continuously hot and dry for several weeks, and yet on 

 no account can such important details be put off an hour if the plants are to pro- 

 duce the finest blooms or make 'perfect specimens. It is often on Sundays that 

 there is a danger of the plants suffering. The plants may be examined in the 

 morning with a view to that watering lasting until the following day, but alter 

 midday the soil in many of the pots has become dust dry, the foliage tlags, and 

 then a serious check results. Again, potting is often deferred too long, and tne 

 roots become so matted together that they do not strike quickly into the new 

 compost when they are potted. It is when plants are allowed to get into tn» 

 unsatisfactory condition that they cannot stand the force of the sun, and the rows 

 are starved and baked by its power on the sides of the pots where they are cnier > 

 located. I do not recommend plunging the pots up to their rims, but wne 

 labour or water is scarce it would be found beneficial and save labour to P* rU * "J 

 do so in a bed of ashes, or the pots may be shielded from the full force ot the 

 by standing nine inch boards on edge against them. A cool, moist bed is nec 

 sary for all pot plants to stand on during dry weather ; but means shouia ^ 

 employed to prevent the roots coming through the draina-e and bee ommg esi» 

 hshed in the ashes beneath, as this may cause the formation of sappy growi • 

 besides which the plants receive a check m the autumn when these outsiae ^ 

 are disturbed and cut off. . 



Portable frames are most useful to the plant grower, as their Pf sitio .^X r in* 

 ™~ to suit the seasons and occupants. Some plant houses are too airy " - 



cerning violets ? " asks the Poet F ~ 

 1 have been asked more than 



n 



# I said nothing con- 

 Poet Laureate, in 4i The Garden that I Love, 



It was -a grave omission, but 



*u — 1_ " 7 "™ * * mm ana occupants, oumt — f cutting. 



the heat of summer for many things, such as seedling ferns, ferns tor _cui b 

 young palms and the like, which delight in a moist shady position, f P ar * [f 

 may be used with advantage for these, giving them an east or west aspe . . 

 suitable blinds are not available to give the necessary shade, common whitening, 



silence \™"«^T7 once - " was a grave omission, but mixed with milk, may be used for smearing the glass over. In this * y 



a re ever^wLre SS^S" 25?** but fr0m thdr P rofusi ™- f n j al atmos P he ^ may be maintaLd if the lights are only slightly 'd^Z 



White ^,11: JSS? Whe , re , will, and everywhere at home. hack, and not in such a way as to cause a draught. Provision Wj^TSS 



" " ' " herbaceous calceolarias and cyclamens, so as to have good stroM p 



before autumn Broad, shallow pans, filled with rich sandy wmoost, J . 

 suitable seed beds. Sow the seed thinly, cover slightly 



as* nv M .mfil miinnt ion takes place. ^ - . secur ^ 



dy, an< 



. " r~* — & »mwh ui a nign lempcwiuic, * cturdv 



after care is necessary to properly harden them and produce a sturay 



Richard Parker, Goodwood Gardens. 



cool 



rrom the land where the boy 



Classic strpptc h*> ..~u 3 



c neat ot summer." Let tne poet come 



classic streets he will fi^TIi* 1 " Mammolc ! Mammole!" In the 

 loves. ' ,U find no lack of them in the garden that he too 



Norwich. 



Edward Peake. 



glass 



ces place, bhade we 

 is most important to raise the young plants, and when this u « ^ 

 prefer it to raising them in a high temperature, as they come up wcak'y, * babit 



