THE PRODUCTION OF POISON IN PLANTS 89 



Greshoff l has indicated that a species of Thymus, the Thymus Serpyllus 

 can be readily distinguished from the variety album phytochemically ; the com- 

 mon form of this species (Thymus Serpyllus} produces thymol in its leaves, 

 whereas the other has the odor of lemons. 



SAPOXINS. We may note here the very wide distribution of saponins in 

 different plants. Greshoff in several papers 2 gives a long list of the orders in 

 which saponin occurs, 1 many of the others are mentioned in the list of species 

 at the end of this manual. 



The substance saponin occurs in many different plants of which the fol- 

 lowing is a partial list: 



Amaryllidaceae : Agave, Fourcroya. Araceae: Arum. Araliceae: Aralia. 

 Begoniaceae: Begonia. Berberidaceae : Berberis, Caulophyllum, Leontice. 

 Bromeliceae : Bromelia. Caryophyllaceae : Acanthophyllum, Arenaria, Dianthus, 

 Gypsophila, Lychnis, Melandryum, Polycarpaea, Saponaria, Silene. Chenopod- 

 iaceae : Chenopodium. Commelinaceae : Tradescantia. Compositae: Arnica, 

 Grindelia, Mutisia. Convolvulaceae : Ipomoea. Cucurbitaceae : Echinocystis, 

 Luff a, Trichosanthes. Dioscoreaceae : Dioscorea. Euphorbiaceae : Phyllanthus? 

 Ficoideae: Trianthema. Filices: Polypodium. Gramineae: Panicum, Lolium. 

 Hippocastanaceae : Aesculus. Illecebraceae : Herniaria. Leguminosae: Acacia, 

 Albizzia, Caesalpinia, Entada, Enterolobium, Gleditschia, Gymnocladus, Milletia, 

 Mimosa, Pithecolobium, Prosopis, Calliandra, Tetrapleura, Xylia e. a. Lili- 

 aceae : Chamaelirium, Chlorogalum, Helonias, Medeola, Muscari Paris, Poly- 

 gonatum, Smilax, Trillium, Yucca, e. a. Loganiaceae: Buddleia. Magnoli- 

 aceae: Illicium. Meliaceae: Trichilia, Walsura. Melianthaceae : Bersama. 

 Menispermaceae : Stephania? Cocculusf Coscinium? Myrtaceae: Barringtonia, 

 Careya. Oleaceae : Chionanthus, Syringa. Passifloraceae : Caricaf Modecca. 

 Phytolaccaceae : Pircunia. Pittosporaceae : Pittosporum. Polemoniaceae : Can- 

 tua. Polygalaceae : Monnina, Polygala. Primulaceae: Anagallis, Androsace, 

 Cyclamen, Primula, Soldanella, Trientalis, e. a. Ranunculaceae : Ficaria, Nigel- 

 la. Rhamnaceae : Gouania, Zisyphus. Rosaceae : Quillaja, Spiraea. Rubiaceae: 

 Basanacantha, Cephalanthus, Mitchella, Mussaenda, Randia. Rutaceae: Zan- 

 tho.vylum. Sapindaceae : Blighia, Dodonaea, Ganophyllum, Koelreuteria, Ma- 

 gonia, Ncphelium, Paullinia, Pancovia, Pometia, Sapindus Serjania. More 

 than 100 species of this family contain saponin. Sapotaceae: Achras, Bassia, 

 Lucuma, Omphalocarpum. Saxif ragaceae : Hydrangea. Scrophulariaceae : 

 Digitalis, Leptandra, Limosella. Simarubaceae : Balanites. Solanaceae: Ac- 

 nistus, Lycopersicum, Scopolia, Solatium. Ternstroemiaceae : Camellia, Cary- 

 ocar. Tiliaceae Grewia. Urticaceae: Ficus. Zygophyllaceae : Guapacum, Tri- 

 biilus. 



HYDROCYANIC ACID. A list of the plants containing a glucoside cap- 

 able of being converted into HCN has been given in another connection, but we 

 may note in this connection plants belonging to many different orders like the 

 Compositae, Euphorbiaceae or Spurge Family, Gramineae or Grass Family, 

 Ranunculaceae or Buttercup Family, Fern, Filices, Droseraceae or Sundew Fam- 

 ily, Saxifragaceae or Saxifrage Family. A common Rocky Mountain shrub, the 

 Jamesia, of this family, is said to contain considerable quantities of HCN, and 



the Mountain Mahogany (Cercocarpus parvifolius) of the Rose Family (Rosa- 







1 Bull. Misc. Information, Royal Bot. Gardens Kew. 1909:415. 



2 Kew Bot. Garden 1909:397. Phytochemical Information at Kew. Mededeelingen uit 

 'S Lands Plantentuin. 29:1909. 



