242 Encyclopaedia of Gardening 



to prevent the plants suffering from sun heat and an arid atmosphere 

 by providing abundant ventilation, by shading, and by damping all 

 surfaces. The plants themselves should not be syringed. For 

 detailed treatment of particular species see a good modern work on 

 Orchids. The following are a few of the best species: citrosmum, 

 rose, white, and yellow, sweet, several varieties. Crispum, white, 

 spotted, but variable in colour ; scores of forms are known, for which 

 consult a special work. Edwardi, purple and yellow, sweet. 

 Grande, yellow and brown, very large and brilliant, several 

 varieties. Hallii, yellow and chocolate, many forms (Botanical 

 Magazine, t. 6237). Harry anum, brown, white, and yellow, several 

 varieties. Luteo-purpureum, yellow and brown, many varieties. 

 Maculatum, chocolate, yellow, and white, several varieties. Nobilis 

 (syn. Pescatorei), white, spotted red, many forms. Pulchellum, 

 purple, yellow, and white, sweet (Bot. Mag., t. 4104). Rossii, white, 

 spotted brown; majus is a popular variety, and there are several 

 others. Triumphans, yellow and brown, several varieties. Uro- 

 skinneri, yellow and brown. Vexillarium is now known as Miltonia 

 vexillaria (see Miltonia) . 



Oenothera, Evening Primrose (Oeno-thera, from oinos, wine, and 

 thera, imbibing, owing to the roots being supposed to stimulate 

 drinking. Ord. Onagrarieae) . Popular and brilliant flowers, not 

 all exclusively night bloomers. They are useful border plants, as 

 they will thrive in most soils, are hardy, and bloom freely. They 

 are propagated by seed, the perennials also by division, preferably 

 in spring. All bloom in summer and have yellow flowers except 

 where otherwise stated. The following are a few of the best: 

 biennis, a biennial, 3 ft. high; grandiflora (syn. Lamarckiana) is a 

 large variety of it. Caespitosa, white, i ft. (syns. eximia and mar- 

 ginata), a perennial. Fruticosa, 3 ft. (Botanical Magazine, t. 332); 

 Youngii is a splendid variety of it; these are perennials. Glauca, 

 3 ft. (Bot. Mag., t. 1606), a perennial; Fraseri is a good variety. 

 Missouriensis (Bot. Mag., t. 1592), is a yellow perennial trailer. 

 Taraxacifolia, white, also a trailer, is beautiful, but not hardy (syn. 

 acaulis) . 



Old Man Cactus (Pilocereus senilis) . See Cactus. 



Old Man's Beard, Clematis Vitalba. 



Oleander. See Nerium. 



Olearia (olea-ria, from olea, olive tree. Ord. Compositae). Use- 

 ful evergreen shrubs. Haastii, which is a dense grower, is hardy, 

 and has attractive white flowers in summer, is particularly good. 

 It grows 4 to 5 ft. high. It may be planted 4 ft. apart in autumn. 

 It is not very particular as to soil, if not stiff and wet. Ilicifolia, 

 also with white flowers, is Musk-scented. Macrodonta is handsome 

 but not quite hardy. Stellulata (syn. Eurybia Gunniana) has 

 beautiful flowers. Propagation is by seeds in a frame in spring, 

 cuttings of mature wood under a hand-light in summer, and by layers 

 in autumn. 



Omphalodes, Navelwort (omphalo-des, from omphales, the navel, 

 and eidos, like, in allusion to the seed. Ord. Boragineae). A small 



