84 OF THE ROOT, 



Helianthus tuber osus, Jacq. Hort. Vlnd. t. 1 61. 

 These knobs are reservoirs of nourishment, mois- 

 ture, and vital energy. Several of the Vetch or Pea 

 kind are furnished with them on a smaller scale ; 

 see Vicla lathyroides, Etigl. Bot. t. 30, and several 

 species of Trifolium, either annuals, as glomera- 

 tum, t. 1063, or perennials, o.sjragiferu?n,t. 1050. 

 The knobs in these instances are only of annual 

 duration ; in the P&onia, Paeony, t. 1513, and 

 'Spinza Filipendula, Dropwort, t. 284, they are 

 perennial. In the Orchidece of Europe tkey are 

 mostly biennial. The root in many of the latter 

 consists either of a pair of globular or oval bodies, 

 f. 10, as in Satyr mm hircinum, EngL Bot. t. 34, 

 Ophrys aranifera, t. 65, and apifera, t. 383 ; or 

 are palmate, that is, shaped somewhat like the 

 human hand,^/. 11, as in Orchis macula fa, t. 632. 

 Of these globular or palmate knobs or bulbs one 

 produces the herb and flowers of the present year, 

 withering away towards autumn, and the other is 

 reserved for the following season, while in the mean 

 time a third is produced to succeed the latter. The 

 knobs of Ophrys spiralis, t. 54 1 , are formed three 

 or four years before they flower, and their flowering 

 appears to be occasionally deferred to a more di- 

 stant period . The root of Satyrium albidum, t. 5 05, 

 consists of three pair of tapering knobs or bulbs, 

 f. 12, which flower in succession. On the contrary, 

 Ophrys monorchis, t.7\, forms its new bulb so late 



