240 



JOURNAL OF HORTICULTUBE AND COTTAGE GABDENEB. [ September 29, 1870. 



the fruiling pinna are reduced to little brown fruiting lobea, 

 which contrast beautifully with the bright green. For a pillar 

 this species is an especial favourite of mine, and it would be 

 one with every Fern-grower if it were better known. This form 

 is a native of the Philippine Islands. 



LYGODICTYON. 



In their general habit aDd appearance the plants composing 

 this genus are exactly similar to the Lygodiums, and they 

 are distinguished from them only by having reticulated veins. 

 This, however, amongst an order of plants in which the ve- 

 nation is of far greater importance than in any other order, is 

 a good and abiding character. The soil and treatment should 

 be the same as for Lygodiums. 



L. Fokstef.i is a very handsome scandent plant, producing 

 bipinnate fronds, which are several times forked in a dichoto- 

 mous manner; the pinna? are oblong-obtuse, the sterile ones 

 longer than the fertile, but the latter are much the broader ; the 

 sori are dark brown, dense, and exserted as in Lygodium, thus 

 rendering it a most attractive plant for rafters or pillars in the 

 fernery. It thrives well in the stove, but it will also attain 

 considerable proportions in a cool house. Native of the Poly- 

 nesian Islands. 



GYMNOG MM 



A genus very popular, and known to most plant lovers by the 

 names of Gold and Silver Ferns, about which I hope to say a 

 few words in a future article. The species to which, however, 

 I wish to draw attention in this place is a climbing plant, and 

 well merits the attention of Fern-growers. It requires a stove 

 temperature, and should be potted in peat and sand only. 



G. flexuosa. — This most elegant plant produces fronds of 

 an indefinite length. The rachis is zigzag, and the pinnre are 

 bi-tripinnate and refracted ; pinnules narrow and somewhat 

 wedge-shaped ; it is entirely destitute of the farinose powder 

 so common to the genus, and dark green in colour. It climbs 

 over bushes and shrubs in its native habitats, and its light 

 graceful fronds produce a charming effect. Native of South 

 America. 



PLATYLOMA. 



This genus contains several very handsome species ; only one, 

 however, can be introduced here as a climber, and it should 

 find a place in every collection of Ferns on account of its ex- 

 treme beauty, its distinctness, and because it succeeds well in a 

 cool house. This genus is characterised by its forked veins, 

 and by the sporangiferous receptacles being terminal and ob- 

 long ; these, being contiguous, form a broad unbroken mar- 

 ginal sorus ; the indusium is linear, continuous, and very 

 narrow. Bough fibrous peat and sand, with a little light loam, 

 suit this genus admirably. 



P. flexuosa. — This is sometimes to be met with under the 

 name of Allosorua flexuosus and Pteris flexuosa ; it is a most 

 elegant plant, and produces a fine effect trained upon a rafter 

 or pillar. The fronds are 6 or 7 feet in length, tripinnate, with 

 a zigzag stem ; the pinnules are small, ovate, and light green 

 in colour ; the sori form a continuous marginal band on the 

 under side, greatly enhancing its beauty. As before remarked, 

 it thrives well in a cool house, and is a native of various parts 

 of South America. 



ADIANTUM. 



Under the name of Maiden-hair Ferns the genus Adiantum 

 is familiar to all lovers of plants. All the Bpecies are hand- 

 some, and some of them rank amongst the most beautiful 

 Ferns in cultivation. The fronds vary from simple to pinnate 

 and bi-tripinnate, with jointed pinna;, which have an excentric 

 costa or midrib ; the veins are forked and free ; the sori mar- 

 ginal, and covered by a conspiouous indusium. Only one 

 scandent species has up to the present time been introduced in 

 a living state to our gardens, although other handsome climb- 

 ing kinds are known to exist in tropical countries. It should 

 be potted in peat and light loam. 



A. Feei is a distinct form of Maiden-hair, and cannot be mis- 

 taken for, or confounded with any other species. It is known 

 in some collections by the name of A. flexuosum. Its fronds 

 extend to a considerable length ; they are tripinnate, having the 

 rachis and petioles covered with a reddish-brown pubescence ; 

 the pinna? are sub-rotund, and dull green in colour. It forms 

 an elegant plant either for pillars or rafters in the stove fernery. 

 Native of Mexico. — Expeeto Ceede. 



Ipecacuanha Cultuee. — According to Nature, there is good 

 report of the progress of Ipecacuanha cultivation in Indis, 

 where it is found so valuable in that prevalent disease, dysen- 



tery. Since Dr. John Murray obtained for it the notice of the 

 Indian Government, it has been successfully planted in the 

 Neilgherries and other of our hill settlements, and in the plains. 

 It has done well even at Calcutta. 



NUTRITION AND SEX IN PLANTS. 



(Read before the American Association for the Advancement of Science.) 

 In my paper on the laws of sex in plants, which I read to the 

 Asiociation last year, I gave some account of a few of the lead- 

 ing facts I had observed, which seemed to indicate that a higher 

 degTee of vigour or vital force was necessary to produce the 

 female than the male sex in plants. I have not met with one 

 fact which has suggested any other conclusion; nor have I heard 

 any fact suggested by others which could lead to any other 

 opinion. Wherever there has been any change in the sexual 

 relations, the male flowers or organs are invariably associated 

 with declining vigour, while only in those parts of plants most 

 favourable t o the highest state of vitality are the female flowers 

 most numerous or generally found. 



This theory is so capable of easy demonstration by anyone 

 who will personally examine the first monoecious tree or plant he 

 meets, that I feel sure nothing further will be needed from me 

 to sustain it. I propose now to go a step further, in the en- 

 deavour to ascertain the exact laws of nutrition, by which we 

 may control these sex-producing forces respectively. 



I have here some specimens of Castanea americana, our com- 

 mon Sweet Chestnut, as my first contribution to this class of 

 facts. 



But first I would call attention to the fact that there are two 

 classes of male flowers in this tree. It is scarcely possible that 

 this should have escaped the eye of other observers, but I find no 

 reference to it in botanical works. One class of male flowers 

 comes out from the axils on half-starved shoots, the other class 

 terminates the strong vigorous shoots which bear the female 

 blossoms. Those of the former class have their flowers set 

 densely on the rachis — on the latter they are somewhat scattered, 

 and do not open until a week or ten days after the latter. The 

 numerous flowers we see on the Chestnut trees are of the former 

 class, and generally have mostly fallen before those associated 

 with the female flowers open. I think it likely that one of these 

 classes does not perform the usual fertilising functions, but could 

 not satisfy myself positively. The interest for us here is to note 

 the antagonism, so to say, between the male and female blossoms. 

 The comparatively weak spikes show that they were formed only 

 after the female flowers had received matter enough for their 

 perfect development. Only the surplus matter goes to form the 

 male flowers at the apex. This is better shown by the fact that 

 often there is no prolongation beyond the female flowers — no 

 male blossoms ; at other times only a few — never, as we have 

 seen, the number which appears on those spikes which are wholly 

 masculine in their nature. 



In regard to the influence of nutrition on sex, another specimen 

 I exhibit is from a tree at least 40 feet high and 6 in circum- 

 ference. It is on my ground, stands out by itself, and has borne 

 fruit regularly and in good crops annually. This year the leaves 

 are all streaked with yellow, as in this specimen. 



Horticulturists well know that this appearance on the leaves 

 of plants arises from an interruption of the nutritive functions. 

 If a branch be partially ringed to induce fruitfulness, or if the 

 roots be injured in transplanting, or rotted by an over-supply 

 of water, a yellow tint to the foliage is the invariable consequence. 

 In some way, then, this Chestnut tree has this season met with 

 some check to its nutritive system, — received a blow to its 

 vitality, which has resulted in this yellow-tinted leaf. The 

 effect of this on the sex is, that though thousands of male flowers 

 are produced, there is not one female flower, one young chestnut, 

 on the whole tree that I can find. 



I think this instance satisfactory as far as it goes, that defective 

 nutrition is one of the agents which operate on those law3 of 

 vitality that govern the sexes. — Thomas Meehan. — [American 

 Gardener's Monthly.) 



GARIBALDI STRAWBERRY. 



I oesebve in your issue of the 8th inst. that a correspondent 

 says the Garibaldi Strawberry which I raised has been proved 

 to be Vieomtesse Herieart de Thury, and that the latter has 

 been sent out under the name of Garibaldi as a new Straw- 

 berry. I beg to deny any such assertion, and farther beg to 

 state that when the Vieomtesse is grown along with the true 

 Garibaldi it will be found that my Strawberry is much superior 



