THEOBROMA TIGRIDIA. 327 



Theobroma (Cacao, Chocolate-tree). Sterculiacece . 



Propagated by ripened cuttings, which should be placed 

 in sand under glass, in heat. 



Thrift. See Armeria. 

 Thrinax. Palmacea-. 



Seeds in heat. 

 Thunbergia. Acanthacece. 



Seeds. Also cuttings of firm wood in a frame, for per- 

 ennials. 



Thunia. Orchidacece. 



As the form of the pseudo-bulbs suggests, this genus is 

 easily propagated by cuttings. These are made about 6 

 inches long and inserted in pots of sand. After standing 

 in an ordinary propagating frame or moist stove for a 

 short time, young growths will appear at the nodes. 

 When large enough they are taken up and potted in ordi- 

 nary compost. Two years, at least, are needed for them 

 to attain to flowering size, but this is the best method 

 where a large number of plants are wanted. See also 

 under Orchids. 



Thuya, including Biota ( Arbor- Vitae, White Cedar errone- 

 ously). Conifers. 



Seeds, which should be gathered as soon as ripe (in 

 the fall) and stratified or sown at once. Shade the seed- 

 lings the first year. Layers. Cuttings of green shoots in 

 summer in a cool frame. Cuttings of ripe wood, as rec- 

 ommended for retinospora. The named varieties are 

 often grafted on potted common stocks in winter or early 

 fall. 



Thyme (Thymus vulgaris]. Labiates. 

 Seeds and division. 



Thyrsacanthus (Thyrse Flower). Acanihacece. 



Seeds ; cuttings made in spring, and placed in a close, 

 warm frame. 



Tiarella. Saxifragacea. 

 Seeds and division. 



Tigridia (Tiger Flower). Iridacea. 



May be increased by seeds, but generally by offsets. 



