688 



THE GARDENERS' MAGAZINE^ 



Jttlt 13, 1912. 



of simple dominance is not known. The 

 hybrid of the first generation is intermediate 

 between the two parents* But this does not 

 negative MendeVs results. 



If we cioes a long-eared wheat with a 

 short-eared, the hybrids are intermediate in 

 length between the two parents. Seed from 

 the hybrids produces three types, long, in- 

 termediate, and short. The proportion is as 

 1:2:1. It is here impossible to fix the 

 intermediate torm as it is and always must 

 be " impure." 



A similar instance is to be seen in the cross 

 between the " Chinese " and "S tar " varieties 

 of primula. The former has large waved 

 petals with ragged margins, the latter has 

 small flat petals with a single notch on the 

 margin. Tlie hybrid between these two 

 varieties is a " blend" of the two characten^ 

 — intermediate in size, petals slightly waved, 

 and with 2-3 r.otdies along the margin of 

 each |)etal. The second generation consistn 

 of 25 per cent. "Chinese," 25 per cent. 

 " Star." and 50 per cent, intermediate or 



" blends." 



•'Chinese" :C "Stai.' 



I 



Intermediate. 



I hinpsc 



Intermediate. 

 50% 



" CInne-ic " Cliincse Inter 



2'i" 



I) 



00% 



1 



Star ' 

 25% 



Star. 



Inheritance of Characters. 



We must now proceed to consider the in- 

 heritance of two pairs of characters. Thus, 

 suppose we cross a variety of pea having 

 round seed and yellow cotyl<Klons (seed 

 leaves), with one having wrinkled seed and 

 green cotyledons, each character will be 

 separately inherited. Since yellow is domi- 

 nant to green, and round to wrinkled, the 

 hybrids of the first generation will exhibit 

 both dominant characters, i.e., the seeds will 

 be yellow and round. In the second genera^ 

 tions the dominant and recessive characters 

 will both be present, each in the proportion 

 of 3 : 1. Out of every sixteen plants, twelve 

 niust be yellow and lour green (12:4 = 3:1). 

 The round and wrinkled characters will also 

 appear in the proportion of 3 : 1. Out of 

 every twelve yellow plants, therefore, nine 

 will be also round and three wrinkled. In 

 the case of the four green, three will 

 be round md one wrinkled. We thus 

 find our second generation to consist of 

 nine yellow round, three yellow wrinkled, 

 three green round, and one green wrinkled. 



This class deserves further analysis, for it 

 shows how we may produce in limited time 

 new varieties, whose characters will breed 

 true. Let Y and R represent the two domi- 

 nant characters and g and w represent the 

 two recessive characters, then the constitu- 

 tion of the two parents will be represented by 

 YR and gw, ^ind the cross YR x gw gives a 

 hybrid with the constitution YR (gw). 



(To be continued.) 



Combretum purpureum.— An 



old-time stove climber from Madagascar, 

 whose scarlet flowers are borne from mid- 

 summer till in many cases autumn is well 

 advanced. The flowers are individually 

 small, and borne in branching panicles, each 

 branch consisting, as it wei*e, of a distinct 

 spike. It is not of particularly vigorous 

 growth hence good flowering examples may 

 be trained round a few sticks, although it is 

 really seen to better advantage when trained 

 to the roof of the stove. This combretum is 

 also known as Poivrea coccinea, and was 

 introduced in 1818. At one time it was re- 

 garded as a good test of the propagator's 

 skill, the cuttings being considered ex- 

 tremely difficult to root, but one hears little 

 of it nowadays. However, like Ipomaea Hors- 

 falliae, young shoots may be readily grafted 



on to pieces of the roots taken from an estal> 

 hshed plant.— W. T, 



WORK FOR THE WEEK. 



♦ 



THE ORCHID HOUSESi 



EPIDENDRUMS.— Besides the on^ men- 

 tioned in the issue of June 29 there are many 

 species of this extensive genus which deserve 

 general cultivation. When strongly g^rown, 

 they produce large panicles of brilliantly- 

 coloured flowers that open in succession for 

 several months, and are extremely useful for 

 table or other floral decorations. Among the 

 brightly-coloured sorts are the Avell-known 

 E. radicans, E. fulgens, E. cinnabarinum, E. 

 il>aguense, and E. xanthinum (bright yellow). 

 The distinct hybrids E. Boundi, E. Dellense, 

 E. O'Brienianum, E. elongatum, and E. 

 radico-vitellinum are also useful orchids, and 

 worthy of cultivation. Those which are o-f 

 semi-scandent habit, like E. radicans and E. 

 Boundi, must be trained to some kind of 

 support; for instance, they may he grown 

 tied up to a wall or pillar, the shoots being 

 fastened to wires, or a wooden trellis. Some 



growers prefer to grow the stems singly in 

 small pots^ using ordinary garden sticks for 

 supports; plants grown in this Way are very 

 useful for decorative purposes. Larger 



be trained round stakes much in 



plants 



the same way as ordinary greenhou 

 climbars are often grown. The plants of this 

 section produce serial roots from their stems, 

 and frequent syringings overhead, are a 

 necessity whilst in full growth. Now that 

 most of these plants have passed, or are 

 about to pass, their flowering stage, and the 

 old shoots having grown very long, those 

 stems with young shoots on them may be cut 

 down to a^bout 2ft. or so in length, and be 

 repotted or replanted. Tliese epidendrums 

 thrive w-all in light positions, either in the 

 cattleya or intermediate house; and for con- 

 venience they should be placed together ; so 

 that they may be syring-ed overhead through- 

 out their period of growth. They will suc- 

 ceed in the same kind of compost as cattleyas^ 

 but must not be potted too firmly ; the 

 drainage, as usual, must be ample. 



OTHER EPIDENDRUMS that are worth 

 growing, although of quite a different char- 

 acter, are E. fragrans, E. atropurpureum, E. 

 Cooperianum , E . sceptrum , E . odoratissi- 

 mum, E. aurantiacuno, with such hybrids as 

 Epi-cattleya matutina, E.-c. Nebo, E.-c. 

 radiata-Bowfingiana, and others, which for 

 cultivation purposes may all be treated as 

 one s-3ction. These and similar plants may 

 also be repotted as soon as growth begins 

 and treated in exactly the same manner. 

 Such kinds as E. Wallisi, E. Endresi, E. 

 Endresio-Wallisi, E. Clarissa, E. elegantu- 

 lum, and E. vitelMnum majus do best when 

 suljected to an even temperature the whole 

 year round, placing them during the summer 

 months in the cool hou&3, and in winter in a 

 cool position in the intermediate house. Now 

 that we have two varieties of E. vitellinum 

 flow^ering at different seasons of the year, it is 

 obvious that the plants will require atten- 

 tion at different seasons. Careful observa- 

 tion will soon decide the proper time when 

 to repot or disturb any plant. These epiden- 

 drums should be supplied with plenty of 

 water at the roots when well eetablisnsd ; 

 but too much care cannot be taken in the 

 application of water to a newly-potted plant, 

 as by an overabundant supply the compost 

 is ruined, and in many cases the plant killed. 

 The plants should be cleaned from time to 

 time, as in many localities red spider is 

 persistent in attacking them, and a weak 

 solution of some safe insecticide will keep 

 them clean, and do them no harm. 



THE WHITE-FLOWERED E. (Diacrium) 

 BICORNUTUM require a higher tempera- 

 ture, the most suitable position being one 

 quite close to the roof glass, in the lightest 

 position in the East Indian house. Estab- 

 lished plants, while at rest, need but very 

 little water to keep them plumb, but when 

 growing they need copious supplies whenever 

 the compost appears to be dry. At this sea- 

 son the plants will begin to grow, and, ati 

 the young roots push out from the new 

 growth fresh rooting material should be 



afforded to those in need of it. This epeciei 

 is best grown in shallow pans, and the com- 

 post as advised for the others will meet its 

 requirements. The rare E. nemorale will 

 succeed under the same treatment. — 

 Barker, The West Hill Gardens. 



CONSERVATORY AND GREEN- 

 HOUSE. 



WINTER-FLOWERING BE<30NIAS, such 

 as Gloire de Lorraine and its white variety 

 Turnford Hall, Mrs. Heal, Agatha, Patti 

 LTdeal, etc., will need constant attentioii 

 now. Young plant., which were rooted early 

 in February, having been potted and kept 

 growing^ are now ready for their final shftt 

 into 6in. pots; this size is large enough for 

 all general purposes, as these begonias, being 

 fine-rooting subjects, do not need a large 

 amount of root room in comparison to the 

 size the plants attain. If very large speci- 

 mens are required for exhibition, 8in. pots 

 may eventually be used, but only for the very 

 largest plants. These begonias resent over- 

 potting and over-watering very much. The 

 best compost to grow them in will be two 

 parts fibrous loam, one part peat or leaf- 

 mould, and one part silver sand passed 

 through an ^in. sieve. The soil should Ije 

 moist and workable, not sticky; it should 

 also be warmed by being placed in the lioucie 

 in which the begonias ar^e growing over 

 night. Make the compost/firm, but do not 

 ram it. These begonias like a fair amount 

 of heat when growing, but they cannot be 

 classed as stove plants. A t-emperature of 

 60 degrees at night dm*ing the siummer, 

 with plenty of moisture overhead suits them 

 admirably ; they mxist also be shaded. 

 Plants subjected to a high temperature he- 

 come drawn and spindly^, and during the 

 winter (their flowering season) the flowers 

 are pale and the flowering season short. A 



temperature of 50 degrees at night and 55 

 by day when in bloom suits them splendidly, 

 and if the plants are staged in a conserva- 

 tory or corridor where these conditions ob- 

 tain they will remain in perfection for 

 months. These begonias are also invalu- 

 able for house decoration. 



PELARGONIUMS.— Show pelargoniums 

 are now practically over, and the plants 

 should be placed outside on an ash-bed in 

 full sun to ripen the growth. In a fort- 

 night the plants will be ready to be cut 

 down, and the cuttings inserted for next 



stock. In all well-ordered gardens 

 of stocks of every class of plants 

 in the gardens should be kept, and 



o up in the potting shed. This can 



referred to at any time, and when batches of 

 plants are being potted it acts as a re- 

 minder for all concerned. The cuttings are 

 best placed three in a Sin. pot. in a sandy 

 compost; kept close for a fortnight the cut- 

 tinge will soon root, and they should be 

 potted up singly directlv they are rooted 

 sufficiently. When the old stools show signs 

 of breaking into growth from the hard stems 

 they should be shaken clear of the old soil, 

 have the roots trimmed, and be potted in 

 3^n. po(t{s. iZonal pelargoniums intended 

 for winter flowering should be potted into 

 32^8 at once, using a rich potting compost. 

 These are best placed outside on an ash- 



years 

 a list 

 grown 

 hung 



be 



bed. 



frequently, 

 be ninched 



The leading shoots should be pinched 



and 

 out. 



all the flower-spikes 



pi] 



OUVARiDIAS 



—Cuttings which were in- 

 serted in April are now making nice plants 

 in 3in. pots and are ready for potting i^^^ 

 48's; the comnost best suited to their needs 



wi 



L ijc loam, peat, sana, wiuu a xillic CJ, f 



rubble and wood ash added. They are best 

 grown in a slightly heated pit, and l^f"^!^ 

 shaded. When growing they should ^ 

 pinched occasionally to encourage a bu^ny 

 habit. Some growers plant their houvai^ 

 dias in beds in the fra^mes, and get g<>oa 

 results also, but the great drawback to tin* 

 method is that the plants often get a severe 

 check when lifting them for potting. 

 this case the ball of soil close to the pjajj 

 should be cut round by degrees a fortnig*| 

 before potting operations commence. — -Lb^ 

 Smith, Shotesham Park Gardens. 



