534 



THE DICTIONARY OF GARDENING, 



Otiorhynclms contin ved. 



mixed with oil, round the tree stems, and along the 

 base of the walls against which Vines and other plants 

 liable to injury are trained. Gas-lime on the soil, or 

 soot or lime, would probably be of service, by preventing 

 the passage of the beetles ; and these applications, with 

 or without paraffin or carbolic acid solutions, or gas- 

 water, would help to destroy the larvae in the soil around 

 the roots of plants. Where a Vine border is badly in- 

 fested, the best course is to remove the soil to a depth 

 of 5in. or Gin. replacing it with new material. Where 

 the beetles are numerous, and destructive to buds 

 and shoots, it is necessary to use means for their cap- 

 ture. They fall very readily off their food-plants when 

 these are shaken, or when a light is brought into their 

 vicinity. Hence, it is advisable to lay cloths or papers, 

 or to invert an open umbrella beneath the plants, which 

 should then be shaken, and the fallen beetles swept 

 together and killed by means of boiling water ; or they 

 may be shaken into rough trays tarred inside. When 

 plants turn sickly without evident cause, investigation 

 should be made, and, if larvas are found, they should be 

 destroyed. 



OTOCHILTJS (from ous, otos, an ear, and cheilos, a 

 lip ; referring to the small, ear-like appendages at the 

 base of the lip). STN. Tetrapeltis. OBD Orchidece. A 

 genus containing three or four species of stove, epiphytal 

 orchids, natives of the Himalayas and Burmah. Flowers 

 more or less conspicuous than in Ccelogyne, loosely 

 racemose; sepals and petals almost equal, free, narrow, 

 spreading ; lip sessile at base of column, saccate at base. 

 Pseudo-bulbs proliferous, two-leaved, continuously pro- 

 duced one above the other, each successive one being 

 emitted just below the apex of the old one, and there 

 throwing out a few fibrous roots; rhizome none. The 

 two species mentioned below require an intermediate 

 house, and an abundant supply of moisture when 

 growing. Pot the plants in peat fibre, pieces of char- 

 coal, and sphagnum. 



O. fragrans (fragrant), fl. white, in erect racemes, 6in. long ; 

 sepals linear-lanceolate ; petals linear ; lateral lobes of lip slightly 

 acute, middle one ovate-lanceolate. June. I. shortly petiolate, 

 oblong-lanceolate, 6in. to Sin. long, plicate. Stem ascendent, 

 short, scaly, terete. Nepaul, 1836. SYN. Tetrapeltis fragrans. 



O. fusca (brownish), ft. sweetly scented, disposed in dense, many- 

 flowered, nodding racemes ; sepals and petals obtuse ; lip golden, 

 tinged with rose; ovary, bracts, column (and rachis) fuscous. 

 August. I. linear-lanceolate. Pseudo-bulbs 6in. to 8in. long, 

 lin. thick, h. 9in. Nepaul, 1810. (B. M. 3921.) 



OTOSTEMMA. Included under Hoya (which see). 



OTTELIA (said to be derived from Ottel, the native 

 name in Malabar). STN. Damasonium. OBD. Hydro- 

 charidece. A genus comprising six or seven species of 

 short-stemmed, stove or greenhouse, aquatic herbs, 

 natives of tropical Asia, Japan, Australia, the Mas- 

 carene Islands, tropical and sub-tropical Africa, and 

 Brazil. Flowers hermaphrodite, in a tubular, shortly 

 bifid, solitary spathe, sessile ; calyx segments oblong 

 or linear, rigid, membranous ; perianth segments much 

 larger, broadly ovate or orbiculate. Leaves clustered, 

 some submerged on short petioles, others long-stalked, 

 floating, ovate-oblong or very broadly cordate. The 

 undermentioned species, the only ones yet introduced, 

 require to be grown in a cistern or pan of water, 

 placed in the stove. Propagation is effected by seeds. 



O. indica (Indian), fl. white, on radical, naked, one-flowered 

 scapes; perianth segments rounclly-obovate, undulately striate, 

 twice as long as the calyx segments. August. I. broadly ovate, 

 about 6m. each way, costate-nerved, very brittle. Rootstock and 

 fibres yellow. East Indies, 1800. (B. M. 1201, under name of 

 Damasonium indicum.) 



O. ovalifolia (oval-leaved).* /., outer perianth segments green, 

 jm. to lin. long ; inner ones pale yellow, liin. to 2in. in diameter ; 

 spathe about liin. long. Summer. I. ovate or oblong, 2in. to 4in. 

 long when perfect, obtuse, rounded at the base, scarcely or not 

 at all cordate. Australia. 



OTTER MOTH (Hepialus Humuli). This insect, 

 which is, perhaps, more widely known by the names 

 " Ghost Moth " and " Ghost Swift," belongs to a well- 

 characterised group of Moths, included under the genus 

 Hepialus, which are popularly known as " Swifts," 

 because of the rapid darting- flight of most of the 

 species. Five species are native in Britain, the Ghost 

 Swift being the largest and most conspicuous, because 

 of the white upper surface of the wings of the male, 

 and its peculiar hovering flight in the dusk of evening. 

 The attraction to the frequented spot is probably a 

 female, concealed among the herbage, above which the 

 male swings almost with the sweep of a pendulum. 

 The popular name of " Ghost " is due to the colour, 

 and to the sudden disappearance of the insect when it 

 settles down among the herbage. 



The Swifts are readily recognised by their antennas 

 being slender and very short, not reaching to the back 

 of the thorax; and, in addition, the wings are long 

 and rather narrow, with a space between the front and 

 hind pairs, on each side, just at the roots. They all 

 fly in the evening twilight. The larvae are long, and 

 rather slender; and in colour are greyish or dull yellow, 

 with a brown head, and a brown, horny plate on the 

 back of the second ring of the body. They feed on 

 the roots of many herbaceous plants, burrowing into 

 those large enough to allow of their entrance. They 

 change, in cocoons spun in the larger, or amongst the 

 smaller, roots, into brown pupas, with long bodies, 

 strongly ringed, each ring bearing short stiff hairs, by 

 means of which the pupas push their way to the surface 

 of the soil before the moths emerge from them. 



The male Otter Moth, in the usual form, as stated 

 above, has all the upper surface of the wings silvery- 

 white, with brown fringes ; but, in the Shetland Islands, 

 varieties occur that show all transitions in colour 

 between the ordinary male and the female. The female 

 reaches about 2-2in. or 2-Jin. in spread of wings, while 

 the male averages only about 2in. The front wings of 

 the female are yellow in colour, with irregular spots, 

 and a broken band near the hind margin, brick-red ; 

 the hind wings are dull leaden-grey at the base, tawny 

 near the margin. The larvae of the Otter Moth, and 

 probably of the common Swift also, sometimes eat roots 

 of Hops, and of a few garden plants, but, fortunately, 

 seldom prove very injurious. The only sign of their 

 presence is the withering of the plants without visible 

 cause. 



Remedies. The roots should be examined, and the 

 larvas of every kind in or upon them should be 

 destroyed. Probably, solutions of paraffin, of carbolic 

 acid, or of other insecticides, would be found beneficial, 

 if the plants were watered with them. 



OTTILIS. A synonym of Leea. 



OURiISIA (so called in honour of Governor Ouris, 

 of the Falkland Islands, from whom Commerson obtained 

 the plant). STN. Dichroma. OBD. Scrophularinece. A 

 genus comprising about eighteen species of mostly low 

 hardy perennial herbs, rarely woody at the base ; six are 

 natives of New Zealand or Tasmania, and the rest inhabit 

 the Andes or Antarctic parts of South America. Flowers 

 often scarlet or pink, whorled, racemed, corymbose, or 

 solitary; scapes bracteate, one or many-flowered. Leaves 

 chiefly radical, petioled, crenate or entire. 0. coccinea is a 

 very ornamental plant for growing in patches, and requires 

 a moist and sweet soil, well drained. A position where it 

 must endure exposure to hot sunshine is fatal to it. It 

 is a slow surface creeper, and should be planted freely 

 in frequented parts of the garden. Propagated readily, 

 by divisions of the roots, in early spring. Similar culture 

 will answer for the other species. The two species de- 

 scribed here are the only ones seen in gardens. 

 O. coccinea (scarlet).* fl. scarlet, with exserted, cream-coloui ed 



anthers, drooping, liin. long, in panicled clusters. May to 



