174 SEEDS 



STRAMONIUM SEEDS 



(Thornapple Seeds, Semina Stramonii) 



Source, &C. The leaves of the thornapple, Datura Stramonium, 

 Linne (N.O. Solanacece) , have already been described (p. 46), and the 

 attention of the student has been directed to the white flower and 

 spiny fruit. The latter when ripe is about the size of a walnut, and 

 dehisces septifragally, the four walls separating from apex to base. 

 The fruit is two-celled in its upper part, but, from the presence of 

 spurious dissepiments, four-celled near the base. It contains a large 

 number of seeds, which are collected when ripe. 





FIG. 95. Thornapple seed. A, showing the pitted 

 surface ; B, longitudinal section, showing curved 

 embryo. Magnified. (B, after Moeller.) 



Description. Stramonium seeds are dull dark brown or, more 

 commonly, nearly black, flattened and distinctly reniform in outline, 

 averaging about 3 mm. in length. The hilum is distinct in the form 

 of a light spot on the concave edge. The seed-coat is marked with 

 distinct, but not sharp, reticulate depressions, and, in addition, is 

 minutely pitted. 



If the seed is split parallel to one of the flattened sides, the crook- 

 shaped embryo may be distinguished embedded in an oily endosperm ; 

 in transverse section the embryo appears rounded, and will, owing to 

 its curved shape, be cut at two, or possibly three, different points. 



The odour of the seeds is scarely perceptible until they are crushed, 

 then it becomes rather disagreeable ; the taste is bitterish and oily. 



The student should observe 



(a) The size, reniform outline, and dark colour, 



(b) The reticulated and pitted surface, 



(c) The curved embryo embedded in an oily endosperm. 



