AN ENCYCLOPEDIA OF HORTICULTURE. 



65 



Qerardia continued. 



usually opposite, the uppermost reduced to bracts of 

 the racemose or paniculate showy flowers. Considerable 

 difficulty is experienced in the cultivation of this genus 

 (owing to its being more or less root-parasitic) ; hence, 

 it is but rarely represented in English gardens. Im- 

 ported seeds frequently germinate, and the plants thrive 

 in rich, friable soil, in a warm, sheltered situation. 



G. pedicularia (Louse-wort). Jl. citron-yellow, varying to deep 

 yellow, sometimes assuming a reddish tint. I. pinnatifid, cut 

 toothed, h. 2ft. to 3ft. United States. Perennial. A smaller, 



but more branching species than G. quercifelia, having smaller 

 and less numerous flowers, about lin. long. (G. C. 1872, p. 43.) 



or less lonj,. 

 uly. I. usually 

 HIS or smooth, 



with merely scabrous margins. Branches virgate, rather spread- 

 ing, h. 1ft. to 2ft. United States, 1772. Annual. A marked 



G. purpurea (purple). Jl. purple; corolla lin. or less long: 

 pedicels shorter than the calyx, mainly opposite. July. I. usually 

 spreading, narrowly linear, either somewhat scabrous or smooth, 



variety of this variable species, G. p. paupercula, 

 B. M. 2048, under the name of G. purpurea. 



figured ii 



G. quercifolla (Oak-leaved), fl., corolla yellow, nearly 2in. long, 

 tubularly campanulate ; calyx large, a little inflated. July ami 

 August. L, lower ones large, bipinnatifld ; upper ones oblong- 

 lanceolate, pinnatifld or quite entire, h. 3ft. to 6ft. United 

 States, 1812. Perennial. See Fig. 100. 



GERMANDER. See Teucrium Cliamaedrys. 



GERMANEA. A synonym of Plectranthus. 



GERMAN IVY. See Senecio mikanioides. 



GERMEN. The ovary. 



GERMINATION. The first act of growth in the 

 embryo plant. Its immediate causes are the presence of 

 moisture, atmospheric air, and a certain temperature 

 above freezing point, varying in elevation, of course, 

 with the nature of the species. Heat excites the vitality 

 of the embryo plant, and enables it to take advantage 

 of the agents with which it is in contact. It has 

 generally been considered that the seed should be ex- 

 cluded from direct light at first, but this has been proved 

 to be quite unnecessary in very many cases. 



GEROFOGON. Now included under Tragopogon 

 (which see). 



GESNERA (named after Conrad Gesner, of Zurich, 

 1516-1565, a famous botanist and natural historian). In- 

 cluding Rechsteinera, OBD. Gesneracece. A genus of 

 about fifty species of very elegant stove perennials, 

 mostly natives of Brazil; a few, however, are dispersed 

 through Guiana, Columbia, and Peru, one extending to 

 Mexico. Flowers disposed in opposite cymes, consti- 

 tuting a terminal thyrse ; peduncles furnished with 

 floral leaves or bracts at the base ; corolla tube often 

 elongated, sometimes distinctly ventricose, often curved 

 and gibbous at the base ; limb regular, or two-lipped. 

 Leaves opposite. The species are mostly tuberous- 

 rooted and herbaceous. 



Cultivation. Propagation is effected by the increase 

 of tubers ; also by cuttings of the shoots, inserted in 

 peat, soon after the plants are started, and by leaf 

 cuttings, detached and put in when they are fully 

 matured. The flowering season of Gesneras may be 

 considerably prolonged by starting successional batches 

 from March until midsummer. Thorough drainage is 

 essential, and peat and leaf soil, with the addition of a 

 little loam and sand, forms a good compost, which should 

 only be pressed moderately firm in potting. The bulbs 

 may either bo grown singly, in Sin. pots, or about five 

 arranged over one 6in. in diameter; they should be 

 covered with lin. of soil, and kept rather dry until 

 growth commences, when the quantity of water may be 

 increased, according to the amount of roots. Shade from 

 bright sunshine, in summer, is necessary, and care must 

 be taken to keep the leaves clean, as in many species 

 these are extremely attractive and beautifully marked. 

 Syringing is not recommended after the leaves are de- 

 veloped ; the water, in nearly all cases, contains lime in 

 solution, and, as evaporation takes place, a sediment is 

 left and retained amongst the minute hairs on the leaves 



Vol. II. 



Gesnera continued. 



of such plants as Gesneras, greatly to their disfigurement, 

 when in flower. The plants succeed best on a moist 

 bottom, such as a bed of coal ashes, in a house kept, 

 in summer, at about 65deg. by night, and, in winter not 

 below 55deg. When flowering is over, they should be 

 gradually ripened and dried off, until all the foliage is 

 dead, when water should be entirely withheld, and the pots 

 stored, with their contents, in a dry part of the stove, 

 where they may remain until starting time the following 

 year. Thrips are frequently very troublesome on the 

 young leaves, and should be carefully looked for and 

 destroyed by fumigating, when in a young state. Spong- 

 ing is sometimes practised, but the leaves are very 

 brittle, and easily broken. If it can be avoided, the 

 plants should not be placed in any house where these 

 insects, or other pests, are present. 



(aggregated). Jl. scarlet ; corolla clavate, cylin- 

 drical; eduncles axillary, one-flowered, aggregate. August. 

 Branches rounded. A. 2ft. 



I. opposite, oblong-ovate, crenate. 

 Brazil, 1816. (B. M. 2725 ; B. K. 329.) 



G. bulbosa (bulbous). Jl. scarlet ; cymes many - flowered, 

 spreading from the axils of the leaves, and disposed upwards 

 in a terminal thyrse. Summer. I. opposite, broad-ovate, cor- 

 date, serrate. Stem erect, h. 2ft. Brazil, 1816. Plant villous. 

 (B. M. 3041.) 



G. chromatella (yellow). jl. rich yellow, drooping, in 

 elegant erect spikes. Summer. I. rich dark velvety. Garden 

 variety. 



G. cinnabarina. See Nmgelia cinnabarina. 



G. cochlearls (spoon-leaved), fl. scarlet, in simple racemes; 

 tube of corolla long, inflated beneath ; limb five-lobed ; pedicels 

 elongated. June to August. /. opposite, on long petioles, cordate- 

 ovate, concave, tomentose, rugose, h. 1ft. Brazil, 1837. (B. M. 

 3787.) 



G. Cooperl (Cooper's).* /. bright scarlet, with a densely spotted 

 throat, drooping. May. I. light green, h. 2ft. Brazil, 1829. 



G. discolor (two-coloured), fl. scarlet, pendulous ; corolla 

 glabrous, clavately cylindrical; pedicels elongated, slender, 

 aggregate. June to September. I. large, opposite, petiolate, 



FIG 101. FLOWERING BRANCH OF GESNERA ELLIPTICA LUTEA. 



K 



