II 



observed at Selborne, Streatham, where a plant of P. Stuartiana 

 had a small portion of a root severed from the main part, clinging 

 to the wood, and remained alive for several weeks without any ap- 

 parent change. Then at the extremity of the small root fragment 

 a projection was noticed, which subsequently developed a dimin- 

 utive leaf. The root then commenced growth again, and when I saw 

 it, it was a quarter of an inch beyond the plantlet. Similar occur- 

 rences have been observed in a few other species. Most of the 

 taller epiphytes appear to produce their roots from any portion of 

 their stem, as in the Vandas and the Dendrobiums, which also 

 affords a means of propagation, or of lowering plants that have 

 become too tall. 



Terrestrial Orchids produce fleshy and fibrous roots that are 

 confined to the soil, and partake more of the nature of ordinary 

 roots. As many of these plants are however deciduous, losing 

 their leaves in the autumn, and as many do not produce 

 perennial stems, they obviously need some store of strength for 

 another season. This is provided by the tubers, which numbers 

 of our British species produce, such as the familiar Orchis 

 mascula, and the principal economic value of the family depends 

 upon the starch or gum (Bassorine) abundantly stored in their 

 tubers. They are sometimes in pairs, or in bunches of several, 

 and the true roots are usually produced from just above them. 

 Some peculiarities occur in certain genera, as in the Bird's Nest 

 Orchid (Neottia Nidus Avis), which has numerous interlacing 

 fibres like a bird's nest, or in the Coral Root (Corallorhiza), and 

 the Epipogium (E. Gmelini), which have curiously twisted tubers 

 resembling Coral. Some member of the three latter genera live 

 in partially decayed vegetable matter, apparently assimilating 

 their food without the aid of green colouring matter (chlorophyll), 

 or true roots, and are termed Saprophytes, being similar to the 

 peculiar Broomrape (Orobanche), and Toothwort (Lathraea). 



THE STEMS. The Orchids, which possess true stems, are 

 chiefly those of the Vanda, Aerides, Saccolabium, and Angraecum 

 type, in which the leaves are produced in a two ranked 

 (distichous) manner on opposite sides of the stem, and produce 

 their flowers from the axils of the leaves. Some of these attain 

 a height of twelve feet or more, and are the giants of the Orchid 

 family, if we except the strange Javan Galeola altissima, 

 which is said to reach 120 feet or more, most others are either 

 very short, as in the tropical Cypripediums ; are pseudo-bulbous, 

 as in the Dendrobiums, or are of annual duration only, as in the 

 North American terrestrial Ladies' Slipper (Cypripedium spec- 

 labile). After a careful study of the vegetative organs of the 

 Orchids at Kew, Dr. Pfitzer, of Heidelberg, has founded a system 

 of classification upon them, particularly upon the stems, and the 

 mode of growth that is detailed in full in the " Gardener's 



