THEOBROMA TIGRIDIA. 327 



Theobroma (Cacao, Chocolate-tree). StercuHacece. 



Propagated by ripened cuttings, which should be placed 

 in sand under glass, in heat. 



Thrift. See Armaria. 

 Thrinax. Palmacea. 



Seeds in heat. 

 Thunbergla. 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- Vitse, White Cedar errone- 

 ously). Coni/ercE. 

 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). Acanihace(z. 



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

 warm frame. 



Tiarella. Saxifragacea. 

 Seeds and division. 



Tigridia (Tiger Flower). Iridacece. 



May be increased by seeds, but generally by offsets. 



