OPHRYS 



OPUNTIA 



1143 



ovate, greenish; petals narrowly linear; labellum long, 

 oblong, purplish brown, with pale white or blue marks 

 in the center; central lobe notched. Spring and early 

 summer. Cent, and E. Europe. R.B. 21:241. 



AA. Margin of the labellum yellow or greenish yellow. 



tenthredinilera, Willd. SAWFLY ORCHIS. Stem 6 in. 

 high: Ivs. elliptic-lanceolate : spike 3-8-fld. : fls. nearly 

 1 in. across ; sepals oblong, obtuse, concave, varying 

 from rose to white; petals very small; labellum broadly 

 obcordate, greenish yellow, pubescent, with a large 

 chestnut - colored spot on the disk. Mediterranean 

 region. B.R. 3:205; 13.1093. B.M. 1930, F. 1872, p. 128. 



lutea, Cav. Stem 4-7 in. tall, many-fld.: Ivs. linear- 

 oblong: fls. % in. across ; sepals oblong, obtuse, in- 

 curved, green ; petals much smaller, linear-oblong; 

 labellum quadrate, golden yellow, with a purple disk. 

 Mediterranean region. B.M. 5941. 



Aceras anthropophora, Br. Advertised as Ophrys anthro- 

 pophora, Linn. MAN ORCHIS. Stem about 9 in. high, the 

 spike being 2-4 in. long: Ivs. ovate to oblong or lanceolate: fls. 

 dull yellowish green ; sepals and petals converging over the 

 column; labellum much longer than the sepals; side lobes long, 

 narrow, and the middle lobe split into two narrow lobes. Early 

 summer. Pastures, S. Europe. Ophrys differs from Aceras in 

 having a very convex labellum. Both genera are distinguished 

 from Orchis by the absence of a spur. 



HEINRICH HASSELBRING. 



OPLfSMENUS (Greek, awned; referring to the awns). 

 Graminece. A genus allied to Panicum, containing 4 

 species of the warmer regions, one of which is cult, in 

 conservatories for ornament. Spikelet 1-fld. ; first and 

 second glume, and often the third, awned. 



1342. Oplismenus Burmannii. 



Burmannii, Pal. (Panicum variegatum of florists). 

 Pig. 1542. A half-creeping perennial, with small, simple 

 panicles, the common form with neatly white and pink 

 striped leaves. Trop. Asia. Popular for edges of beds 

 and for hanging baskets. Propagated by divisions of 

 the rooting stems. Gn. 47, p. 68. ^ g. HITCHCOCK. 



OPIUM is the product of Papaver somniferum, the 

 common annual summer-blooming poppy of our gar- 

 dens with smooth, glaucous leaves. 



OPOPANAX. See Acacia. 



OPUNTIA (old Latin name used by Pliny, later used 

 for the Indian Fig, thought by some to be derived from 

 Opus, a town in Greece: by some authors the name 

 is said to have been derived from a small port, Opus, 

 in South America, from whence plants of the Indian 

 Fig were early exported to the Old World). Cactacece. 



Opuntia is a genus of great variation in habit and ap- 

 pearance, and, from the frequency of natural hybrids 

 and ill-defined specific lines, one of the most difficult 

 genera of flowering plants to satisfactorily present in 

 systematic order. Opuntias vary from small, prostrate 

 plants a few inches above the ground to trees with 

 spreading tops 20 or more feet high. The steins are flat, 

 clavate or cylindrical, and bear more or less elevated 

 areolro, from each of which appears a small caducous 

 pointed leaf, rarely spreading and foliar. An oval or 

 circular area, more or less covered with soft wool, inter- 

 mixed with barbed bristles and usually a variable num- 

 ber of spines, occurs in the axil of each leaf. The 

 flowers are borne singly toward the upper portion of 

 the joints or stems, on the bristle-bearing part of the 

 areola, and have spreading,. showy corollas. The usually 

 many-ovuled inferior ovaries are not of foliar develop- 

 ment, and sometimes differ but slightly in appearance 

 from normal stems. They are usually bristle- and spine- 

 bearing. Fr. dry or succulent, frequently edible; seeds 

 large, flattened, discoid and often margined. Some of 

 the forms of Opuntias are seen in the illustrations 

 (Figs. 1543-1549). 



Some of the largest Cacti are Opuntias, while nearly 

 all that are of economic value belong to this genus. The 

 genus numbers about 130 species and many varieties 

 and hybrids. It extends from British America south- 

 ward through the United States, Mexico, West Indies and 

 Central Americato the southern portion of South America. 

 The species are confined mostly to arid and semi-arid 

 regions; however, some are found in regions of heavy 

 rainfall. They are found in greatest quantity and variety 

 of species in southwestern United States and northern 

 Mexico, where they are often trees and form the most 

 conspicuous part of the flora. A few species are ex- 

 tensively cultivated in warm regions for their large, 

 edible fruits, while others are grown as hedges. Where 

 introduced, many species have escaped from cultiva- 

 tion and become dangerous and troublesome weeds. 

 Although the Opuntias are less attractive as pot-plants 

 and, on account of their barbed spines and bristles, 

 more difficult to handle than most other Cacti, they are 

 coming into favor on account of their unique appear- 

 ance, rapidity of growth and attractive fls. They grow 

 best with an abundance of heat and sunlight, the char- 

 acter of the soil being a secondary consideration. Like 

 all other Cacti, they require perfect drainage. They are 

 readily grown from cuttings, and also from seed under 

 proper management. 



Economic Value. Economically considered, the 

 Opuntias are by far the most important of the Cacti. 

 Although originally confined to the New World, the 

 more important species are now in cultivation or have 

 escaped from cultivation and become wild in every arid 

 and semi-arid region of the globe where the tempera- 

 ture permits their being grown. Wherever grown, their 

 tendency is to escape from cultivation and become per- 

 sistent and troublesome weeds. In this respect they 

 are much more to be dreaded iri foreign countries than 

 in America, the place of their nativity. 



Ornamental Value. As ornamental plants, Opuntias 

 are unique rather than pleasing. From their stiff, for- 

 mal aspect they do not harmonize, as a rule, with other 

 plants, and on account of their spines and bristles they 

 are difficult to handle and are considered by most gar- 

 deners as a nuisance in decorative planting. It is as 

 hedges and as groups of mixed species that they are 

 most effective. 



Most species grow rapidly and bloom profusely. The 

 fls., as a rule, are large and showy and of various colors, 

 although yellow predominates. They soon wither after 

 blooming and remain at their best only for a few days. 

 The spines and bristles which usually cover the base of 

 the fls. render them of no value as cut-flowers. With 

 many species, such as O.' leptocaitlis, O. tetracantha, 

 and some forms of O. Tuna, the bright-colored fruits, 

 which remain on the plants for a long time after ripen- 

 ing, render them more attractive in fruit than in flower. 

 Crested or fasciate forms (Fig. 1543) are common. 



The Fruit of theOpuntias. Although extensively culti- 

 vated for their fruit in many countries, where they fur- 

 nish an important article of diet for 4-5 months each 

 year, they do not as yet take a pomological rank with the= 



