212
VARIATION IN BOMBAY STRIGAS.
BY
W. Burns, D. Sc.,
Economic Botanist, Dept. of Agriculture, Bombay.
The present paper is a preliminary note embodying scattered observations on variation in species of Striga found in the Bombay Presidency.
In the course of the writer's investigation of the flora of Indian grasslands he frequently found Striga species. Many of these seemed to be imperfectly described in floras. A closer study of these species was therefore made. It will be convenient to take these one by one.
I. S. lutea : A species of wide geographical distribution, given in the floras of Hooker and Cook for India, Trimen for Ceylon, and Mueschler for Egypt. Pearson mentions its occurrence in South Africa where it is a serious pest on maize. In the Bombay Presidency it is a pest of jowar (Andropogon Sorghum) and bajri (Pennisetum typhoideum).
A. In these floras, in the species keys and descriptions the number of calyx ribs of the species is given as follows:
- Hooker: Key, 10-15; Description, 10-ribbed, rarely 15-ribbed,
- Cook: Key, 10-15 ribbed, ribs of the calyx most commonly 10; Description "Calyx . . . with one strong hirsute rib running from the base of the calyx to the apex of each tooth, and with 1 (less commonly 2) secondary ribs between them, which terminate at the sinus."
- Trimen: Key and description, 10.
- Mueschler: Key 10-17 ribbed; 10 ribbed; Description, generally 10 ribbed.
- Van Buuren, a graduate of the Poona College of Agriculture, and now in the Ceylon Department of Agriculture, in his paper[1] on Root Parasitism in Some Scrophulariaceae of Western India, states that S. lutea is usually 10 to 12 ribbed.
The above descriptions would seem to indicate a certain amount of variation in the number of calyx ribs, and the writer has found this to be the case in even the small number of specimens studied by him personally. 11 ribs are common. One plant gave flowers having respectively 11, 14, and 13 ribs. Another gave 11 and 13, and two others 14 and 13 on each plant. On one plant 15 ribs were found in
- ↑ Poona Agricultural College Reports No. 1.
