

The Crystals in Datura Stramonium L* 



By Henry Kraemer 



The value of the study of the distribution of crystals of calcium 

 oxalate in plants from a systematic standpoint has been demon- 

 strated by R. V. Weltstein in an exhaustive study of the members 

 of the family Umbelliferae. In some, if not all of the members 

 of the family Solanaceae, are to be found in one or more elements 

 (root, stem, leaf, etc.) cryptocrystalline crystals of calcium oxalate. 

 These are also referred to by different writers as " Sable tetrae- 

 drique " or as " Krystallsand." In the genera Atropa and Solatium 

 these crystals occur uniformly in some of the parenchyma cells of 

 roots, stems and leaves. In some other genera, as in Hyoscyamus, 

 these cryptocrystalline crystals may be replaced for the most part 



- 



by monoclinic prisms or pyramids and in still other genera, as in 

 Datura Stramonium L., by rosette aggregates and other crystals. 

 The form of the crystals as well as their distribution in the mem- 

 bers of the family Solanaceae will, no doubt, prove of significance 

 in the developmental history of the genera comprising this order. 

 In the root of Datura Stramonium L., we find in the parenchyma 

 of the primary cortex, numerous cells which possess a very large 

 number of small cryptocrystalline crystals of calcium oxalate 

 which are more or less deltoid in shape and from 2— io/i in their 

 longest diameter. On account of the small size of these crystals 

 there are likely to be some differences of opinion as to which 

 system they belong. Vesque describes them as "Sable tetrae- 

 drique, M indicating that they are hemiedral forms of the isometric 

 system. But inasmuch as calcium oxalate crystals are only 

 known to occur in the monoclinic or tetragonal systems it seems 

 that they are probably hemiedral forms of either one or the other 

 of these systems. It would appear that part of the crystal was 

 formed and that the formation of the remaining part was either in- 

 terrupted or disturbed. It is not at all unlikely that further investi- 

 gations will demonstrate that they are hemiedral forms of the 



* Presented at the Columbus Meeting of the American Association for the Advance- 



of Science. 



(37) 



