560 TAXACEiK EQUISETACE.i:. 



Salisburia, Sm. {Spreng. syst. 3, p. 763, No. 3128 ; — Endl. gen. pi. 1, p. 

 262.) 

 l.adiantifolia, Sm. {Spreng. syst. 3, />. 865 ;— /2oa^6. H. B. p. 68. — 

 Ginkgo biloba, L.) b Japan. Was introduced into H. C. G. in 1806-7, 

 but had not fl. up to 1814. Seeds large and eatable. 



* Podocaipus neriifolius. Lamb. (Lignum Emanum, Rumph. 3, t. 26.) 

 b Amboyna. — P. latif alius. Wall.; pi. as. rar. 1, t. 26. b Khassya 

 Mountains. — P. taxifolius, Kth. b N. Granada. Peru. — P. verticilla- 

 tiis, Hortul. 5 Japan. 



ORDER CCXXIV.— EQUISETACE^, DC— Lindl. Nat. Syst. p. 317. 



THE HORSE-TAIL TRIBE. 



Leafless, branched herbs, found in ditches and rivers, comprehended un- 

 der one genus. Of these, Spreng. syst. assigns 13 species to Europe, nearly 

 all of which are likewise common to other parts of the world ; 3 to S. 

 America and the W. Indies, and 1 to N. America. His species require, 

 however, to be thoroughly re-examined. In the E. Indies, according to 

 Royle, have been found 3 species, natives of Nepal, Kunawur, and Silhet. 

 One of these is also common in Bengal, Dindygul, and Burma. 



" In economical purposes the Equisetum are found highly useful, for po- 

 lishing furniture and household utensils ; a property which is due to the 

 presence of a great quantity of silex in the cuticle. According to the ob- 

 servations of John of Berlin, they contain full 13 per cent, of siliceous 

 earth. {Ed. P. J. 2. 394.) The quantity of silex contained in the cuticle 

 of Equisetum hyemale, L. {E. B. 13, i. 915,) is so great, that Sivright 

 succeeded in removing the vegetable matter and retaining the form. {Grev. 

 fl. edin. 214.) Brewster observed these siliceous particles beautifully ar- 

 ranged in two lines parallel to the axes of the stem. From these observa- 

 tions, it has been concluded, that the crystalline portions of silex and other 

 earths found in vegetable tissues, are integral parts of the plants them, 

 selves." {Lindl.) 

 Equisetum, L. {Spreng. syst. 4, p. 4, No. 3215 ; — Endl. gen. pi. I, p. 



58.) Horse-tail, 

 l.debile, Roxb. (H. B. p. 75 i—Wall. Cat.—E. pallens, Wall. Cat.) %. 



Dindygul. Burma. Bengal, (Serampore.) Silhet. Northern Doab. Dey- 



ra-Dhoon. Fl. R. S. 



* Equisetum diffusum, D. Don. (E. scoparium. Wall. Cat.) Nepal. — E. 

 Inglisii, Royle. Kunawar. — E. bogolense, Kth. New Granada. — E, 

 giganteum, Spreng. W. Indies. 



