460 



HENDERSON'S HANDBOOK OF PLANTS 



TRE 



in choice collections. See Tetratheca and 

 Platylheca. 



Tremandra'ceae. A Bmall order of heath-like 

 shrubs, all Australian, with small, entire 

 leaves often verticillate, and red, blue, or 

 rarely white flowers, on slender axillary ped- 

 icels. The order contains three genera and 

 over twenty species. 



Trenching. This is a means of preparing the 

 soil but little practiced in the United States, 

 though still much in use in old English gar- 

 dens. It consists in malting a trench from 

 one and a half to two feet deep, and of nearly 

 the same width, the earth from which is 

 wheeled to the rear of the ground to be 

 trenched ; then a line is set across the bed to 

 the width of the excavation (one and a half or 

 two feet, as it may be) ; the top spit of this is 

 thrown in the bottom of the trench, the under 

 part being thrown on the top; in a word, 

 trenching is simply reversing the soil, turn- 

 ing it upside down to such a depth as may be 

 decided on. The practice is proper enough in 

 soils that are deep enough ; but when trench- 

 ing is practiced in say a top soil only twelve 

 Inches deep, and a clayey sub-soil is thrown 

 on the top, or even mixed well with the top 

 soil, injury may be done to the soil from 

 which it will never recover. A sub-soil of 

 sand is not quite as bad thrown on the top or 

 mixed with the soil, but in either case the sub- 

 soil should only be loosened, as in sub-soiling 

 (which see), and allowed to remain without 

 being mixed with or thrown on the top of the 

 soil proper. 



Treve'sia. Called after the family Treves de 

 Bonfigli, at Padua, who were supporters of 

 botanical research. Nat. Ord. Araliacem. 



A genus, numbering eight or nine species, 

 natives of tropical Asia and the Malayan Archi- 

 pelago. T, eminena and T. palmala, the best 

 known species, have beautiful, large, palmate, 

 or pinnately-divided, leaves, and make very 

 ornamental plants for a warm conservatory, 

 and are propagated easily by cuttings. Syn. 

 Gaslonia. 



Trevo'a. Named in honor of Treoo, a Spanish 

 botanist. Nat. Ord. Rhamnacem. 



A small genus of interesting green-house 

 shrubs, natives of South America. T. trineroia 

 and T. quinquenervia are in cultivation, fcut 

 seldom found except in botanical collections. 



Trew'ia. Named in honor of J. C. Trew, of 

 Nuremberg, a botanical author. Nat. Ord. 

 EuphorbiacecB. 



A small genus of stove-house plants, natives 

 of the East Indies. T. nudiflora, the only spe- 

 cies in cultivation, thrives best in a compost 

 of sandy loam and leaf mould. It was intro- 

 duced in 1796, and is readily increased by 

 cuttings. 



Triadelphous. Having the stamens collected 

 into three distinct bundles, the filaments of 

 those in separate bundles cohering. 



Tria'nea. Named in honor of M. Jose Triana, a 

 botanist and traveler in Columbia. Nat. Ord. 

 HydrocharidacetE. 



A genus of green-house, stoloniferous plants, 

 natives of Mexico and South America, now 

 regarded by Bentham and Hooker as synony- 

 mous with lAmnobium. 



TRI 



Trichl'mum. From trichinos, hairy; flowers 

 covered with knotted hairs. Na,t. Ord. Ama- 

 ranthacece. 



A genus of annuals and herbaceous peren- 

 nials from Australia. The flowers of some of 

 the species are extremely ornamental. Their 

 yellow, crimson, white, or pink flowers, are 

 produced in terminal heads or spikes. The 

 perennials require to be grown in the green- 

 house. The annuals should be started in seed 

 boxes In February, as our seasons are too 

 short for their development if the seed is 

 sown in the border. 



Trichooe'ntrum. Prom thrix, trichos, fi hair, 

 and centron, a spur or centre ; alluding to the 

 long, thin spur of the labellum. Nat. Ord. 

 OrchidacecB. 



A considerable genus of epiphytal Orchids 

 from South and Central America. Most of the 

 species are not considered worth growing. T. 

 albo-purpureum, from the Rio Negro, is an 

 exceedingly beautiful plant. Petals maroon- 

 brown inside, and yellowish-green outside , 

 lip large, white, with two bright purple spots. 

 T. Pfavii and one or two other species have 

 very beautiful flowers. They should be grown, 

 on blocks or cork, or in small baskets in a 

 moderate temperature. They bloom freely, 

 and require but little care. Introduced in. 

 1835. 



Triohode'sma. From thrix, trichos, a hair, aiid 

 desmos, a bond; the anthers are bound to 

 each other by hairs. Nat. Ord. BoraginacecE. 

 A genus of strigose annuals, natives of 

 India, Egypt and South Africa, with the habit 

 of Borago and Cynogloaawm. T. aeylanicum, 

 Ceylon Borage, the only species in cultivation, 

 is a rather coarse, hardy annual, with blue 

 flowers, thriving under ordinary treatment. 



Tricholae'na. From thrix, trichos, a hair, and. 

 chlainar, a cassock. Nat. Ord. Oraminacece. 



A small genus of very pretty grasses, gener- 

 ally included in the genus-Pamcum. A few- 

 are found in collections of ornamental grasses 

 in the green-house. 



Tricho'manes. From thrix, trichoa a hair, and 

 manoa, soft; the shining stems appear like 

 soft hair. Nat. Ord. Polypodiaceoe. 

 ' An extensive, varied, and beautiful genus 

 of Ferns, found abundantly in the moist, 

 shady woods of the tropics in both the Old 

 and the New Worlds. T. radicana, a beauti- 

 ful species, is found on the coast of Ireland. 

 Many of the species are cultivated lor the 

 beauty of their fronds, which have an almost 

 transparent appearance. Propagated by divis- 

 ion or from spores. Feea, Hymenoaiachya, 

 Involucraria, Lacoatea, Lecanium, Miorogoniuvt 

 and Phldnophyllum, are now included in this 

 genus, which comprises over one hundred 

 species. 



Triohone'ma. From thrix, trichos, a hair, and 

 nema, a filament; stamens clothed with ml- 

 nute hairs. Nat. Ord. Jridacece. 



A genus of beautiful little crocus-like, buU 

 bous plants, with red, yellow, purple and white 

 flowers, borne' singly on slender scapes. They 

 are natives of Spain, Italy, and the Cape vt 

 Good Hope. Like most bulbs from those 

 localities, they require to be grown in the- 

 green-house. Propagated by offsets. Intro* 

 duced in 1818. Called also Romuka. 



