THE GARDENERS' CHRONICLE 



TTTTranse, and the flowers yellow in both, and 



**\ «• w e large, thick, undulated, and variegated. 

 ** tiger chiefly in the inflorescence, which in the 

 2^ kaft and narrow, with close pressed bracts; and 

 J*i -£, n d shor: and broad, with great spreading 

 ^vrrose) bracts. Both are Brazilian, from Bahia, 

 Sodaced by M 



117 



■■■■ 



VEGETABLE PATHOLOGY.— No. LX. 

 ~*>68 Apostaxis. — Constitutional and Organic* or 

 Afodetdal.—^" Gumming. — The fluid contents of the 

 Liu in a vast variety of plants hold either in solution 



other 



n a vast >»* ic v v * j/*—^ *x V .^ ^«»,.^ A mmm «v»«v.v^ 

 pension a variety of matters differing from each 

 in more or less important characters, known 



arabine 



pectiue, not truly 



while others, like the 



v. 



ramui ^i^***~-7 - r — — » -- — — 



Soluble, the other merely capable of swelling up and 



Some of these, like 

 hers, 

 lile ot 

 irts, oi 



of SWi 



becoming soft under the presence of water. The formula 

 if pure gum is C 12 H n llf or identical with that of 

 Ctoe Sugar, and in consequence its transition into starch 

 C lt H l0 l0 , or the contrary, is asimple subtraction or 

 addition of water, while its conversion into cellulose 

 whose formula is identical, is a matter of equal facility, 

 provided there be light and heat enough for the 

 forpoee. In due proportion, gum is, in fact, one of 

 the most indispensable vegetable constituents. Besides 

 these gums, or their allies, which become hard 

 when dry, another substance called mucilage, differing 

 [n being less hard when dry may be contained in the 

 fluid of the cells, and in the course of fermenta- 

 tion a viscid matter often arises, producing the appear- 

 ance which is called ropiness, which when dry approaches 

 my closely to the characters of arabine. Both in health, 

 therefore, and disease, the cells may be gorged to a 

 greater or less extent with these matters ; and it is 

 efcyious that in many cases where they are formed in great 

 abundance it may be necessary for health to eliminate a 

 portion, or the rupture or decomposition of cell walls 

 may set a portion free which might otherwise have 

 been retained without inconvenience. A portion of these 

 gummy matters finds a receptacle in the intercellular 

 passages which, in some cases of disease, are in conse- 

 quence greatly distended. A portion, again, is poured 

 out into especial reservoirs or ducts, as in the gum ducts 

 rf the shoots of the Lime, or the bassorin bags of salep, 

 where they are ready for any exigency without being 

 present in the general fluid to such an extent as to 

 impede its motion ; but even where there is no especial 

 deposit of gummy matters in particular cavities, the sap 

 is often so highly charged as when emitted to dry in a 

 few minutes into a gelatinous globule. 



269 To a small extent, again, elimination may 

 take place through the stomates without any lesion 

 of the cell walls. The little transparent free 

 globules which occasionally occur, hardening on pro- 

 longed exposure to the air on young shoots, as 

 * tne Vine, when vegetation is active, are probably 

 «ne to such a cause, and the sebaceous matter which 

 occurs ion the leaves of several plants may some- 

 «nes have a similar origin, as is certainly the case with 

 •one ^ other substances, as for instance manna. The 

 quantity of gummy matter, however, which escapes in 

 jw way is comparatively small. In the Acacias, which 

 J« gum Arabic, and the Goat Thorns from which the 

 flna tragacanth or bas 

 tod many other plants, 



, 



*nre 



oozes, in Anacardium 



,_ . k . - - r «j the production amounts to 



jmething very considerable in the course of the year. 



Sl S i qUl ^ im P° ssibIe in the se cases that the process 

 «^a take place without the rupture of the cells, whether 

 poceemng from the general tissue or gum sacs in the 

 ££, *na indeed whatever may be the mode in which it 

 ftewair e f n u Ut| T hether bv sim ple percolation through 

 of their I °t lls 0r ° ther cavities , ov in consequence 



an ontl J UP -T e ' e accumulft ted matter could never find 



The Jn! W1 fc a ru P ture of the superincumbent bark. 

 ^c n 8 eq Uence9 Qf ^ ^.^ ^.^ ^^ ^ ^ 



"""■W in the cases mentioned, have not, as far as I am 

 ™? n * tud ' ed m^utely. Those species which are 

 ^en en!? T P henomen on in their own warm climate, 

 <* in othJ J 11 0ur conserv atories do not exhibit it, 



*ol«riw « 8 they d ° not form more 8"™ than is 

 fcease h necessar y for th V* exigencies. Whatever be 



Mormon, r^? WUh the exotic P lants wh «ch yield such 

 *he simiL q UleS 0f S um >+ t«e evils which result from 

 «* nnhann i pr ° CesS in our Plum9 aud oth er stone fruit 

 *etfow of not ° nou8 to every cultivator. The first 



^ous wav« gUn i the Cella ° r duct8 ma y arise in 



* «oncentr»* : *. may be lhe cons equence of too great 



^ed hn? n the Bap ' as where branches are 

 fleeted • Z „ Iy " 0r ' far more > where the y are de ' 

 ^ence nf Ce ° r . daets m ^ be ru P tu *"ed either in con- 



kweak ann ? eC8Blve heat or cold > the cel1 w *lls may 



* kd drain ased b ? reason of ungenial temperature 



^tities asTV ° r the gum may be de P osited m such 

 *** has arZ a naasa g e ; b ut iu every ca$e where 



te ywural r ° trudedfromthecel,s there is seld °ni 

 ln ^hich £ es * at,cm of the process. As the cavities 



k* «UDnlv • gUm Was contain e d are emptied, a 

 *• orisinal 1S C0n6tautI y poured in from behind, 

 Nuance i Up ?; rabundai ice being kept up from the 



?* Ov erflow i 8ame causes which fir8t produced 

 ****> which m , tbe first instance, the point of 

 ^r—r^l ma y be traceable either to the wood or 



bark, may be almost microscopic, but if it is watched 

 it will be seen to extend gradually, and as gum alters in 

 consistence with every alteration of the hygrometer or 

 with every shower of rain, there is a constant action of 

 external moisture on the cells — a circumstance which 

 very rarely takes place without producing decomposition* 

 The gum in consequence alters in colour, beiug impreg- 

 nated with ulmine or allied substances, and disease and 

 decomposition gradually extend till the whole circum- 

 ference of the branch or trunk is corroded, and the tree, 

 wholly or in part, perishes. From the very nature of 

 the case it is difficult to apply a remedy. The first 

 indication is to avoid every circumstance of climate 

 or of treatment which may induce the condition, to pre-* 

 vent the effect . of sudden ^changes from drought to 

 excessive moisture by keeping the ground properly 

 moist by watering or mulching in very dry seasons, to 

 keep the branches thin and properly pruned, so that the 

 gum which is contained in the general current of sap 

 may be fully elaborated and not poured out too fast 

 into the gum ducts, on account of its superabundance, 

 and when the disease condition has once been set up, 

 to cut out with a very sharp knife as cleanly as possible 

 the affected parts. When collodium can be obtained 

 at an easy rate, it may probably become a useful item 

 in such processes, as it will exclude the outward air, 

 and possibly prevent the first flow of gummy matter 

 from the wound made by the knife, which might after- 

 wards lead to a renewal of the evil. 



270. The exusion of gum is sometimes a mere 

 symptom of disease, as in many of the cases just men- 

 tioned and in the affection which has of late years been 

 so prevalent amongst Cucumbers and Melons. The 

 walls of the cells are in parts unable to resist the 

 pressure upon them, and their fluid contents in conse- 

 quence ooze out. This is equally the case in the 

 Cucumber disease in the fruit and branches, and it is 

 I believe one reason of the distortion, especially at the 

 upper part of the fruit, which is so common a feature of 

 the disease. 



bottom heat of 85° or 90°, and maintain a temperature 

 of 75° to 85 °, syringing the plant over head frequently 

 in bright weather, but be very careful in the application 

 of water at the root for some time after potting, and 

 use means to ascertain the exact state of the soil before 

 watering at all, giving enough at each application to 

 thoroughly moisten the ball, and no more until it is 

 absolutely wanted. When the sun becomes powerful, a 

 thin shade for a few hours on the forenoons of bright 

 days will be useful, and will obviate the necessity for 

 giving much air, and allow of keeping the atmosphere 

 moist ; but shading must be used sparingly. If all 

 goes on well the plant will make very rapid growth, and 

 soon fill its pot with roots ; and when this is the case, 

 shift into a 15-inch pot, using the same compost, &c, as 

 for the last shift. Apply the trellis at once on which it 

 is to be flowered, and train the shoots neatly and regu- 

 larly to it, taking care to well cover the bottom, and 

 return the plant to bottom heat, and where it can be 

 liberally supplied with warmth and moisture. The 

 same caution in watering will be necessary until the 

 roots get hold of the fresh soil as after the former shift. 

 It is astonishing how vigorously this plant will grow 

 when kept in a warm and properly moist atmosphere, 

 and carefully attended to ; and with good management 

 it should cover a large trellis, and be in full beauty, by 

 the middle or end of June. 



271. An interesting case is mentioned by Meyen, in 

 which large masses of gum were deposited in the 

 pith of a Cycad, so as in great measure to replace 

 it. A large and very old stem of an Encephalartos, in 

 the royal garden at Potsdam, refused under any mode 

 of treatment to send out roots. It was at length divided, 

 and many large cavities, one alone attaining the dimen- 

 sions of 4-5 cubic inches, were found in the pith filled 

 with brown gum, whether by some decomposition of the 

 juices intended to supply the fecula of the pith or of the 

 fecula itself J, or by immediate exusion from the woody 

 cylinder did not appear. The excessive formation of 

 pectic acid in certain roots which are known by the 

 Indians of North America under the name of Tuckahoo, 

 will be considered under a future Number. M. J. B. 



When the specimen is fairly set with flower, an 

 sional watering with manure water made from sheep 

 dung will be of great service in maintaining the vigour 

 of the plant, and will also increase the size and colour of 

 the flowers. Where it can be avoided this Dipkdenia 

 should never be removed to the conservatory, or to a 

 cool-house while in bloom, for although with care in 

 preparing it for the change it may* be placed in a cool- 

 house for a few weeks when in full bloom, its beauty is 

 soon over, and its flowers soon become smaller and 

 much paler when removed from heat, and it should be 

 allowed to remain in the stove in bottom heat all the 



J£^*" 0f thecW^^ 9 1 ? is P urel y functional, it hardly 



DIPLADENIA CRASSINODA. 



Under good management this is one of the most 

 useful of stove twiners, but to have it in anything like 

 perfection, a warm moist atmosphere and careful treat- 

 ment are indispensable. It is easily propagated ; cuttings 

 selected of rather weak young shoots when about 

 3 inches long, slipping them off with a heel, root readily 

 if properly treated. The cuttings should be planted in 

 a well- drained pot in sandy peaty soil, covered with a 

 bell-glass, and plunged in a brisk bottom-heat, taking 

 care not to overwater them, as any excess of this 

 element would be apt to rot the tender cuttings. As 

 soon as they are perceived to be moderately rooted, pot 

 them singly in small pots in a mixture of good strong rich 

 peat and decayed leaf-soil, well incorporated with plenty 

 of silver sand. After potting, the young plants must 

 be placed in a warm moist situation, kept close, and 

 shaded from bright sunshine until they get established. 

 There is no situation so suitable for the plants after 

 potting off, or indeed while vigorous growth is wished, 

 as a properly worked dung-pit. 



As soon as the pots get filled with roots attend to 

 shifting into larger ones, and do not allow the plants to 

 receive any check for the want of pot room, until they 

 are well-rooted in 6 or 7-inch pots. The cuttings should 

 be put in as early in spring as they can conveniently be 

 obtained, in order to allow of having them good strong 

 plants before winter. I will suppose, however, that a 

 good vigorous healthy plant in a 6-inch pot is in stock, 

 and intended to be grown into a good specimen for 

 blooming this summer. Turn the plant out of the 

 pot at once, and if the ball is covered with 

 healthy active roots, shift into an 11 -inch pot, using the 

 same soil as recommended for young plants with 

 the addition of a small proportion of thoroughly-decayed 

 cow or sheep dung, and some clean small potsherds or 

 lumpy bits of charcoal. Let the compost be broken up 

 into nice lumpy pieces, selecting only the very prime ; 

 and have the mould when used in a proper state as 

 to moisture, and also at about the same temperature 

 as the ball of the plant ; and in potting make the fresh 

 soil rather firm about the old ball. Apply a trellis, 

 and train the shoots thinly and regularly to it ; and keep 

 them regularly tied in as they advance in growth, bear- 

 ing in mind that a larger trellis will have to be applied, 

 and that, if the shoots are allowed to get entangled or 

 twisted around the wires, they will be troublesome to 

 take off the trellis. After shifting, plunge in a brisk 



t Morren believes that the gum ducts of Cycads are certainly 

 supplied by the abundant fecula, acted on by an acid produced in 

 the leaves, and he is inclined to generalise on the production of 

 gum in other cases. Certain it is at least that in the gum-bear- 

 ing Acacia fecula is deposited in great quantities in the ducts of 

 the stem. 



summer, where it will bloom for months in succession. 

 Towards autumn the supply of water to the soil should 

 be limited in order to get the wood well ripened, and it 

 will require very little in winter, when it sliould be kept 

 comparatively inactive for some two months. Although 

 I greatly prefer young plants to old specimens that have 

 bloomed, having always found them to grow more 

 vigorously and produce finer foliage and larger higher 

 coloured flowers, the latter are not to be disregarded 

 where proper young plants are not at command. The 

 present is the proper time for starting old plants into 

 growth, particularly if they are wanted for the June 

 and July exhibitions. The shoots should be removed from 

 the trellis, turning the plant out of the pot, reducing the 

 ball as much as can be done without injuring the 

 stronger roots, and carefully cutting away any bits of 

 the tubers or roots that are found to be diseased. Repot 

 in the same sized pot, and plunge in a brisk bottom 

 heat, but give no water to the soil until active growth 

 commences. Only maintain a moist atmosphere, and 

 syringe the plant lightly morning and evening. Let the 

 trellis be applied at once, and after cutting out all weakly 

 shoots, and shortening the others to strong well ripened 

 wood, train the shoots thinly and regularly over the 

 trellis, and otherwise attend to the plant as directed 

 above. Alpha. 



OAK PLANTATIONS. 



The writer of the following lines, believing that he 

 has for many years past adopted and carried out a 

 system most conducive to the growth of Oak timber, 

 and which may be seen in its various stages from the 

 seedling to the large tree in the near neighbourhood of 

 the New Forest, desires to call the attention of those 

 taking an interest in the present questions of what is 

 right and what is wrong in the management of the 

 Royal Forests to the simple method adopted by him, to 



keep the woods at in full crop, robust health, and 



luxuriant growth. This has been accomplished after 

 much observation of, and comparison between, kindly 





growing woods and those of a contrary nature, by 

 I endeavouring to secure to the latter, as far as possible 

 by artificial means, the advantages which soil and situa- 

 tion have supplied to the former, the most important of 

 these being complete drainage and necessary shelter, 

 the first by open ditches, the second by planting Larch 

 or Scotch Fir, the first as the best nurse in old neglected 

 j woods, the last in newly enclosed moors or heathy 

 ground — thick planting in each rase being essential, but 

 in the last the young Oaks are not introduced until the 

 Firs have become of sufficient size to thin, by which 

 time they will have so prepared the ground by shading, 

 and the decay of their leaves and other woody and vege- 

 table substances, that the Oak will soon overtake them in 

 growth, and require especial attention. Here the care and 

 judgment of the forester become of the most vital im- 

 portance to the future welldoing of the plantation, which 

 if properly and timely thinned, so as to give headroom 

 and yet shelter to the now growing Oaks, they will, in a 

 fewyears, begin to overtop the nurses, and may by degrees 

 be so inured as to bear exposure to every wind except 

 the south-western, which in Hampshire is the prevailing 

 one, and against the effects of which great care should 

 be taken, by having some old Fir nurse trees inter- 

 mixed with the Oaks for shelter; indeed this would be 

 found beneficial on all exposed sides of the plantation, 

 and ought never to be overlooked. 



Whether in old natural woods or in new plantations, 

 the writer has found it of the utmost importance to rear 

 the Oaks thickly, and thin them out gradually, thus 

 j causing rapid growth, And by keeping up the shelter 



i 



