The Structure and Development of the Haustorium 
of Striga lutea. 1 
BY 
EDITH L. STEPHENS, B.A., F.L.S. 
With Plate XCIII. 
O TRIG A LUTEA , Lour. 2 (the Witch weed or Rooibloem — ‘ Red Flower’) 
is a semi-parasitic annual belonging to the Order Scrophulariaceae. It 
occurs in scattered localities throughout Zululand, Natal, and the Transvaal, 
on various native grasses and also on Zea Mays , which is an important 
South African food-crop. Its life-history is now being studied by Professor 
Pearson, to whom I am indebted for the supply of material and for much 
helpful information as to its life-history and mode of growth. Most of the 
material investigated was collected by him on the maize crops in the 
Transvaal; the remainder was obtained from cultures of Striga on the 
maize reared in this laboratory. 
The Plant. 
Striga lutea is a root parasite which passes a portion of its life-history 
underground in the form of a slender white shoot bearing scales, leaves, and 
numerous adventitious roots. Later, the shoot grows above ground into 
a slender green-branched stem, 2 to 18 inches high, bearing decussating 
pairs of linear leaves and spikes of bright red flowers. 3 4 The adventitious 
roots arising from the underground portion of the shoot branch freely and 
come into contact with the root-system of the maize plant on which the 
seedling parasite has established itself. The roots of host and parasite form 
a network in which those of the Striga plant are readily distinguished by 
the absence of root-hairs, by their transparency and paler colour (the endo- 
dermis of the maize showing through the cortex and giving the root 
a yellowish tinge), and often also by the presence of small patches of 
a reddish secretion (giving reactions for mucilage) on their surface. At 
points where roots of the two come in contact or approach one another 
1 This investigation was assisted by a grant from the Union Government. 
2 Fide Flora Capensis, vol. iv, sect. 2, p. 445. 
3 See figure of plant, Burtt Davy (’ 04 ), Plate LXXIV a. 
[Annals of Botany, Vol. XXVI. No. CIV. October, 1912.] 
4 A 2 
