THI 



[ 778 } 



THR 



TKIBAT/DIA. (Named after Thiclaut.de 

 Berneaiid, a French botanist. Nat. ord., 

 Whortleberries [Vaceiniacejfi]. Linn., 8- 

 Octandria 1-jWonogynin.) 



Stove evergreens. Cuttings of half-ripe shoots 

 in sand, under a bell-gLiss, and in moist heat ; 

 sandy loam and fibry peat. Winter temp., 5(1 

 to 60; summer, 60 to 85. 



T. macra'ntfia (large-flowered). White, yellow, 

 red. December. Moulmein. 1840. 



macrophy'lla (large-leaved). White. K.Ind. 



microphy'lla (small-leaved). 2. September. 



Peru. 1847. 



pulche'rrima (beautiful). 10. Red, green. 



May. India. 1845. 



gla'bra (smooth). 6. Deep rose. Sep- 

 tember. Columbia. 



seti'gera (bristly). Scarlet. Khooseea. 1837. 



vaccinu'ceu (cranberry-like). Khoostea. 1837. 



variega'ta( variegated). Scarlet. Khooseea. 1 837. 



THINNING. The exhaustion consequent 

 upon the production of seed is a chief 

 cause of the decay of plants. This ex- 

 plains why fruit-trees are weakened or 

 rendered temporarily unproductive, and 

 even killed, by being allowed to ripen 

 too large a crop of fruit, or to " overbear 

 themselves." 



The thinning of fruit is, consequently, 

 one of the most important operations of 

 the garden, though one of tbe least gene- 

 rally practised. It. is equally important 

 to be attended to in all fruit-bearers, but 

 especially the vine, nectarine, peach, apri 

 cot, apple, and pear. It should be done 

 with a bold, fearless hand ; and the per- 

 fection of that which is allowed to remain 

 will amply reward the grower, in harvest 

 time, for the apparent sacrifice made. But 

 he will not reap his reward only in this 

 year, for the trees, thus kept un weakened 

 by over-production, will be able to ripen 

 their wood, and deposit their store of sap 

 in their vessels, so absolutely necessary 

 for their fruitfulness next season. 



Thinning is a most necessary opera- 

 tion with plants as well as with the fruit 

 they bear. The roots of a plant extend 

 In a circle round it, of which the stem is 

 the centre. If the roots of adjoining 

 plants extend within each other's circle, 

 they mutually rob of nutriment, and 

 check each other's growth. Thinning in 

 the seed-bed is generally applied with too 

 timid a hand. 



THISTLE. Ca'rdiws*. . 



THOMA'SIA. (Named after Messrs. 

 Thomas, two brothers, collectors of Swiss 

 plants. Nat. ord., Byltneriads [Byttneri- 

 acese]. Linn., 5~Pent<utdria~L-Mon</(jt/nia. 

 Allied to Lasiopetalum.) 



Greenhouse/'New Holland, evergreen shrubs. 

 Cuttingi of firm, stubby, young side-shoots in 



sand, unrfer a bell-glass, in April ; sandy, fibry 

 loa:n and peat, with a little charcoal and broken 

 pots, and pots extra well-drained. Winter temp., 

 40 to 48 ; a sheltered, airy place in summer. 

 T. cane'scens (hoary). - Purple. June. 1835, 



di/'u'sa (straegling). White. April. 1822. 



dumo'sa (bushy). 2. White. May. 1326. 



fuliu'sa (leafy). 3. June. 1823. 



glutinti'srt (clammy). Red. May. 1342. 



grandiflo'ra (large-flowered). Red. 1840. 



paniculn'ta (panic-led). Red. June. 1842. 



piiU'iflo'ra (few-flowered). Red. June. 1848. 



purpu'rea (purple). 3. Purple. June. 1803. 



qutsrcifu'lia (oak-leaved). 3. Purple. May. 



J803 



solan'i'ceti (potato-like). 3. White, June. 1803. 



stipu/a',-ea (large-stipuled). 3. Red. 1842 



triphy'lla (three-leaved). 3. June. 1824. 



THORN-APPLE. Datu'ra. 



THOROUGH-WAX. JBupleu'rum rotundi- 

 fo'/ium. 



THOUI'NIA. (Named after A. Thouin, 

 professor of agriculture, &c., in Paris. 

 Nat. ord., Soxpworts [Sapindaceoa]. 

 Linn., 8-Oclnndria l-Monoyynia. Allied 

 to Nephelium.) 



Stove evergreen shrub. Cuttings of firm side- 

 shoots in s>and, under a bell-glass, in heat; sandy, 

 fibry loam and a little peat or leaf-mould. Win- 

 ter tc-mp., 50 to 58; summer, b'0 to 85. 

 T. pinna' 'ta (leafleted). 8. White. New Spain. 

 1823. 



THRIFT. (Sta'tice.) See EDGING. 



THBI'NAX. (From thrimix, a fan; 

 shape of the leaves. Nat. ord., Palms 

 [Palmacere]. Linn., Q-Htxandria l-Mouo- 

 g H nia.} 



Stove Palm. Seeds in a moist, sweet hotbed, 

 in spring ; rich, loamy soil. Winter temp., 55 

 to 6(> ; summer, 60 to 90. 



T.parvifla'ru (small-flowered). 15. White, green, 

 Jamaica. 1/7&. 



THRIPS. Thrips Adonidum is one of 

 the worst pests that can gain a footing 

 iu out stoves and greenhouses. The 

 Lirvse and pupre are yellowish-white, and 

 the perfect insect is of a dull, deep black, 

 with the point, and sometimes the whole 

 of the abdomen, of a rust colour; the 

 wings are divty white;' the horns and 

 legs yellowish, the extremity of the for- 

 mer black. It attacks plants by piercing 

 the under side of the leaves; and one 

 often sees, at the tip of the tail,. a globule 

 of blackish fluid, which it soon deposits, 

 and, by innumerable spots of this gluti- 

 nous matter, the pores of the leaves are 

 stopped up, and large portions of the 

 surface become blotched. During March 

 the full-grown lame and pupae, which 

 are as large as the perfect insect^ are 

 found in groups, feeding on the under 

 side of the leaves ; and at this time the 

 recently -hatched but perfect insect either 



