Page:Illustrations of Indian Botany, Vol. 2.djvu/132
64
ILLUSTRATIONS OF INDIAN BOTANY.
come more and more imbedded in (he lignious system of the support, owing to the deposition of the new wood of the latter. The fibres of the parasite never penetrate bevond their original attachment, although the later developed fibres appear to have the power of arriving at this point, but no further. This is very remarkable. In the adult plant the sucker bearing shoots frequently run to a considerable distance, many of the stocks being literally covered with parasites, all of which have originated from one seed. I have seen such shoots, which had taken their course along a decayed branch, become reflexed, and return in quest, as I may express it, of a part capable of affording due nourishment. In all the species of Loranthus which I have examined the same phenomena occur, and also in the species of Viscum from which the drawings were made. I have reason to believe, however, that in some Loranthi and Visca the attachment takes place by one spot; in other words, that there is only a primary attachment : such will approximate in form to be Viscum album.
"The sucker-bearing shoots frequently run contiguous to each other, and are occasionally reciprocally united by "suckers;" in such there is actual communication between the lignious system."
As already observed nearly all the plants of this order are parasitic, the genus Nuytsia is mentioned as the only exception, but Mr. Griffith informs me that he once found a terrestrial Loranthus. An occurrence so unusual, almost leads one to suspect that the plant in question can scarcely belong to that genus. All the species of Loranthus and Viscum are shrubby with jointed branches and succulent leaves. On this account they are very troublesome plants to dry, being apt to break at each joint, and to lose their leaves in the process, and when dried are scarcely worth the trouble, from the difficulty of examining their structure after having undergone that operation.
"Calyx with a smaller calyx, or bracteae, at the base of its tube : limb short, entire or lobed. Petals 4-8, free or more or less united : aestivation valvular. Stamens as many as the petals, and opposite to them : filaments more or less combined with the petals : anthers versatile, or erent, or adnata. Ovarium cohering with the tube of the calyx, 1-celled: ovule solitary : style filiform or almost wanting : stigma capitate. Fruit fleshy, crowned with the calyx, 1-celled, endocarp membranaceous and tough, or somewhat crustaceous, marked with several longitudinal nerves. Seed solitary. Embryo straight, in the axis of a fleshy albumen : radicle next the hilum, thickened or truncated at its extremity. Shrubs, almost all parasitical. Leaves fleshy, entire, opposite or rarely alternate, sometimes wanting."
Affinities. On this head I feel constrained at once to acknowledge my ignorance, knowing no order with which I can compare this. In so far as the solitary pendulous ovulum affords a mark of relationship, I should consider Loranthaceae akin to Alangieae which is further established by the viscid pulp, by which in both families the seed is surrounded, and by albumenous seed with a superior radicle. Add to these the alternate exstipulate leaves, common to both, and the analogy ceases, unless some further indications of relationship be found on a comparison of the early stages of the ovula. But even these points seem to me of sufficient importance to have attracted the attention of Botanists who have hitherto sought in vain for its relations. By a similarity of structure in the ovarium and seed, they are related to Corneae, from which they are said to be principally distinguished by the stamens being opposite the petals in Loranthus, alternate with them in Cornus. The relationship to Alangieae, just indicated, seems to have been overlooked on account of the one family having polypetalous, the other monopetalous flowers, a distinction assuredly not without value, but of very secondary importance, as compared to the structure of the ovarium and fruit especially in this family, one of whose leading genera, Viscum, is polypetalous. The same structure, namely monopetalous flowers, has caused this order to be viewed as nearly related to Caprifoliaceae, though their ovary, ovules, and seed are widely distinct. Brown, the ablest Botanist of the present day, and of all living Botanists the most intimately acquainted with the structure and affinities of Proteaceae, an order which he has deeply studied, points it out as related to Loranthaceae, an affinity mentioned on his authority by most recent writers, but by all, in such terms as to convey the impression that they could not detect it. I am not myself very intimately acquainted with either order and therefore do not attempt to examine the question, but I have the authority of Mr. Griffith, who has studied Loranlhaceae with very great care, for stating that "every