Oat 



( 122 ) 



Octomeria 



of tannic acid in many of the larger kinds of galls, 

 these abnormal growths have a distinct com- 

 mercial value, and enter into the manufacture of 

 ink and leather. 



The principal galls and insects are the Cherry 

 Galls on Oak leaves (Cynips Quercifolii); Oak 

 Apples, or King Charles' Apple (Andricus termin- 

 alis) ; Silk Button Gall (Neuroterus numismatis) ; 

 Oak Spangles (Neuroterus lenticularis) ; Currant 

 Gall (Spathegaster Baccarum) ; Devonshire or 

 Marble Gall (Cynips Kollari) ; and the Ink Gall 

 (Cynips tinctofia), the last produced on the 

 Levantine Oak, Quercus .fligilops. Oak galls are 

 formed on the leaves and twigs, and sometimes on 

 the roots. 



OAT (see also AVENA). 



The several species of Avena, known collectively 

 as Oats, are all handsome Grasses, and the majority 

 are of immense value to the human race, as the 

 grain is extensively used for horse and cattle 

 feeding, and among the poorer classes is in some 

 countries made into bread. It also enters largely 

 into the composition of some patent foods, while 

 as oatmeal or rolled oats it is the basis of a nutri- 

 tious breakfast dish that as " porridge " has for 

 generations been extremely popular among the 

 Scots. 



OBERONIA. 



A genus of about fifty low-growing epiphytes 

 (ord. Orchidacese), chiefly natives of India and the 

 Pacific Islands. The flowers are very interesting, 

 the late Dr. Lindley remarking that in Oberonia 

 '-' Pythagoras would have found a living evidence 

 of animals transmuted into plants." A stove tem- 

 perature suits. Increase is by division. A little 

 peat and sphagnum placed about the roots, and the 

 whole attached to a small block of wood or placed 

 in a tiny Teak basket, will suffice in the way of 

 potting. 



Principal Species : 



iiiini.-it.-i. 10", sum., ver- 

 milion. 



rufilabris, 6", sum., yel. 

 to red. 



tahitensis, 8", Jy., or. 

 (tyii. iridifolia of Bot- 

 anicnl Magazine 4517, 

 not of Lindley). 



OCA. 



This is the name given by the Bolivians to the 

 tuberous and farinaceous roots of Oxalis tuberosa 

 and 0. crenata, which are largely employed as a 

 food. 



OCHNA. 



Stove evergreen shrubs (ord. Ochnacese). Prop- 

 agation, by cuttings in summer, in sand, beneath a 

 bell-glass, over bottom heat. Soil, sandy loam and 

 fibrous peat, with plenty of grit. In some species, 

 and especially in multifiora, the black and crimson 

 fruits are most attractive. 



Principal Species : 



atropurpurea, 4', spr., multiflora, ">' to 6', sum., 

 pur. yel. 



OCHROCARPOS. 



Stove trees (ord. Guttiferse). Propagation, by 

 suitings of ripe wood in sandy peat, beneath a 



Oali-lcaf Geranium (see Pelargonium quercifo- 



Hum). 



Oitlt, She (see Casiiarina stricta). 

 Oblioniter Tree (see JEiculiit Hij/pocastanum). 



bell-glass, over bottom heat. Soil, fibrous loam 

 and sand. 



Principal Species : 



africana, (10', sum., grn. (syn. Mammea africana) 



OCHROMA. 



Stove evergreen trees (ord. Malvaceae), the wood 

 of which is so light that it is employed for corks 

 in the West Indies. Propagation, by cuttings in 

 sand, beneath a bell-glass, over bottom heat. Soil, 

 mellow loam and sand. 



Principal Species : 

 Lagopus, 30 , My., wh. tomentosa, 25', My., wh. 



OCHROPTERIS. 



Stove Ferns (ord. Filices). The only species 

 is pallens, 4'. Propagation, by division. Soil, 

 three parts fibrous peat, one part loam, and 

 coarse sand. 



OCHROSIA. 



Stove evergreen trees (ord. Apocynaceos). They 

 respond to the same treatment as Ochroma. 



Principal Species : 



borbonica, 10', My., pale yel. (syn. Cerbera bor- 

 bonica and C. undulata). 



OCIMUM. 



Half-hardy annuals and shrubs (ord. Labiatse). 

 Propagation, by seeds sown under glass, or on a 

 warm border out of doors in May. Any rich, deep 

 soil suits. The only member of note in the genus 

 is Basilicum, the common Basil (see Basil), and 

 one of the most useful pot herbs. 



Other Species : - 



canum, 1', Jy., grh., wh. sanctum, 1', Jy., grh., 

 gratissimum, 4' to 8', Jy., pur. (y. Lumnitzera 



grh. shr., wh. teuuittora), 



OCOTEA. 



Greenhouse trees (ord. Laurinere). Propagation, 

 by cuttings of ripe wood in sandy peat beneath a 

 bell-glass. Soil, sound loam with coarse sand. 



Principal Species : 

 bullatu, 15', sum., grn. calit'oniica (see Umbellu- 



(.11/11. Oreodaplme bul- lariiv califoruica). 



la'ta). 



OCTADESMIA. 



This genus (ord. Orchidaceje) consists of about 

 three West Indian species, all epiphytes. Prop- 

 agation is by division. Sphagnum, fibrous peat, 

 and broken crocks form a suitable potting mixture. 



Principal Species : 



serratifolia, 6", aut., wh., buff (syns. montana 

 and Octomeria serratifolia). 



OCTOMERIA. 



Interesting little Orchids (ord. Orchidacese), 

 closely allied to Pleurothallis. Warm greenhouse 

 treatment, fibrous, peat and sphagnum, and plenty 

 of water at all seasons, are the chief cultural 

 points. 



Principal Species : 

 (liaphana, 4", Ap., grn., saundersiana, 6", win., 



yel. yellowish pur. 



graminifolia, 6", My., serratifolia (nee Octades- 



wh., spotted red. mia serratifolia). 



supraglauca, 3", aut., 

 grn., yel., pur. 



Oc/ira>it!ie (see Titrpinia). 



