LANTANA IN CEYLON. 303
the latter; the modus operandi obviously being that it grows taller, and, by its large leaves, keeps out the sunlight, without which the Lantana cannot exist. No doubt some report of this has been carried to Hawaii. I do not think, however, that Tiihonia has ever yet been sown in Ceylon with the object of destroying Lantana; indeed, one weed is little better than the other.
There is no difficulty in obtaining seed in any quantity.
Colombo, Director, Royal Botanical Gardens.
- August 15th, 1891.
Trimen does not appear to have made any direct publication on the subject.
Ceylon botanists at the present time would hesitate to affirm that Tiihonia kills out Lantana to any marked extent, though where the two grow together the process described by Trimen may operate. This is assisted on waste land by the side of the railway by the periodic cutting back of the vegetation, as Tiihonia develops a large stool from which new shoots spring up rapidly after cutting and smother slower-growing species. But Tiihonia appears to prefer damper localities than Lantana. It is especially luxuriant along the banks of rivers, and here in many cases it occupies the lower parts of the sloping banks while Lantana flourishes in the drier upper parts. As regards their relative status as weeds, — it is more difficult to get rid of Tiihonia than Lantana, because of the more extensive develop- ment of the rootstock of the former.
Tiihonia diversifolia was not introduced into Ceylon with the object of killing out Lantana. It was introduced as a garden plant in 1851, and soon escaped from cultivation. Seeds were, however, sent to Hawaii for that purpose.
The author of the Memoir states that Lantana is reported to have been introduced into Ceylon about 1824 and that it is probable that it reached India about the same time. It is very difficult to fix the dates of introduction into Ceylon of the earlier exotics, as few of the early records are extant. This is no doubt due in part to the frequent changes of Superintendents during the twenty-five years following the removal of the Botanic Garden to Peradeniya, as these changes must have made it impossible to establish any proper organ- isation. Moreover, owing to lack of adequate office room and furni- ture, records were stored in cases on the verandah of the Superinten- dent's bungalow, where they were inevitably destroyed by white ants. There is also the further extenuating fact that on the death of each
862—40
