\ 



ILLUSTRATIONS OF INDIAN BOTANY. 63 



LXXX. -LORANTHACE^. 



* 



A curious and widely distributed order of parasitical plants, abounding in species but with 

 very few genera,seven onlybeing enumerated by Meisner, the latest writer to whom I can refer 

 for upwards of 400 species. DeCandoUe refers about 330 species defined by him to 3 penera,* 

 but some of these are certainly imperfectly known and others may be repetitions, which the 

 author had no opportunity of detecting by comparison of specimens : but to set against these 

 many have since been discovered, which will probably suffice to maintain the numbers nearly 

 as here stated. In their habits the order is most remarkable, being with a very few exceptions 

 parasitic, growing upon, insinuating their roots into the substance, and drawing their nourish- 

 ment from the juices of living plants, a property, known to be possessed by very few cotyle- 

 donous plants in the whole circle of the vegetable kingdom. To fit them for this mode of 

 propagation, their seed are covered with a viscid glutinous substance, which adheres tenaceous- 

 ly to whatever it comes in contact with, and retains it there, until circumstances favourable for 

 exciting vegetation occur, when it pushes forth its radicle, the extremity of which it curves 

 towards its support, on reaching which it becomes enlarged and flattened having the appear- 

 ance of a sucker. From this enlargsment the fibrous roots emanate, spreading themselves on 

 all sides between the wood and the bark. In course of time, as the branch thickens by subse- 

 quent depositions of wood, these roots become gradually embedded in its substance, not by 

 their power of penetrating it, but simply by new deposits over them. Though the space I have 

 to devote to the subject is now greatly reduced, I cannot deny myself the pleasure of enhancing 

 the value of my work by introducing a rather long extract " on the mode of Paritism," from a 

 very able paper by Mr. Wm. Griffith,lately published in the Linnean transactions " on the ovula 

 of Lorantbus and Fiscuin." 



*• The only species in which this has been studied in any detail is the Fiscum albutn, and 

 even here the statements are not altogether satisfactory. The latest account which I have'seea 

 is that of DeCandolIe in his excellent Physiologii Vegetate, vol. ii. p. 790, and more fully 

 in vol.iii. p. 1409, where the subject is treated in the usually luminous manner^ so characteris- 

 tic of this distinguished author. 



" The mature seeds of all the species of Loran/^M* adhere strongly to the substance on 

 which they are applied by means of the viscous matter. This viscum soon hardens, and then 

 has the appearance of a transparent glue. The first changes take place in L. scurrula two or 

 three days after application, and consist of a curvature of the extremity of the radicle towards 

 the support ; this extremity when it reaches this point becoming enlarged and flattened. 



*' It has now the appearance of a sucker, such as those, for instance, of the Qassytha 

 filiformis. I am unable to state the precise manner in which the radicle penetrates the bark. 

 The operation seems to require some time, and it is not until it is completed that the plumula 

 begins to be developed. In those species the cotyledons of which are soldered together, the 

 plumula passes out by one of the clefts ; in the others by the fissure between these two bodies. 

 The cotyledons in all the species I have examined remain inclosed in the albumen, which sub- 

 stance begins to disappear as soon as the plumula commences to be develop ed ; the cotyledons 

 undergoing a corresponding diminution in size. By the time that the young plant is furnished 

 with a pair or two of leaves the attachment will be found considerably firm. If we cut away 

 the portions of the support, and lay bare the included portion of the parasite, we find that the 

 application takes place entirely between the lignious systems of both, the fibres of the sucker- 

 like root of the parasite expanding on the wood of the support in the form of a ftte cVoie, 

 There is, however, no interchange of structure between them ; neither at this period is there 

 any intermixture of lignious fibres. As soon as the young parasite has acquired the height of 

 two or three inches, when an additional supply of nourishment is probably required, a lateral 

 shoot is sent out, which is, especially towards the apex, of a green colour. This at one or two 

 and subsequently at various places, adheres to the support by means of sucker like productions' 

 .which are precisely similar in structure and in mode of attachment to the original seminal one! 



" As the parasite increases in size, these lateral shoots become frequently very numerous 

 and give origin, I believe, always from tho^p parts immediately opposite to the sucker like ad- 

 hesion likewise to stems and branches. During the same period the fibres of the suckers be- 



