ON THE PARASITISM OF OROBANCHE MAJOR. BY EDWARD PARFITT. BIBLIOGRAPHY. Vaucher, M., In Memoir du Museum, vol. x. p. Sutton, C., Linnean Society's Transactions, vol. iv. p. 173. Smith, Sir J. E. p. 163. LAST autumn my friend Professor Dickie suggested to me the desirability of investigating the history and physiological relationship of Orobanche major to the plant on which it grows, and this spring I took up the investigation; and as the plant grows within an easy distance of Exeter, I have been enabled to watch its progress. Some may be curious to know the etymology of the word Orobanche. Pliny says, “A weed there is which we named Orobanche, for it choketh eurile (ervuni, a kind of vetch,) and other pulse." The word is derived from orobus, vetch, and ancho, to strangle, and is by some called strangle tare, as it was supposed to kill the plants on which it grew. To the early relationship or parasitism I must plead my ignorance, except through the study of the writings of others, as I have not sufficient time or opportunity for studying it through all its various stages. At the same time, I considered that the history of its parasitism would not be complete, if I did not include its early history as well as its later life. Orobanche major, according to Mr. Hewit C. Watson, has its southern limit in Cornwall, Isle of Wight, and in Kent; and its northern range is in Northumberland and Dumfries; at the same time our English type has a geographical range through between 50° and 56° of latitude. OROBANCHE MAJOR. Fig. i. Longitudinal section of root of furze, with a plant of Orobanche attached, and showing the roots of the latter traversing the furze root. Fig. ii. Transverse section of the same root. Fig. iii. Large cellular mass or axis of parasite. Fig. iv. Two young plants of Orobanche. Fig. v. Parts of the medullary rays growing into cellular mass of the Fig. vi. Elongated cells forming the roots of the parasite, highly Fig. vii. Roots of the parasite flattened and enlarged. |