334 



HENDERSON'S HANDBOOK OF PLANTS 



PLE 



India. Handsome plants of easy culture, first 

 introduced in 1840. 



Plectopo'ma. A group of hybrid Gesneras, 

 •which some writers have constituted a distinct 

 genus. They are a strong, erect-growing 

 class, with but little to distinguish them from 

 others of this interesting order. 



Plectran'thus. From plektron, a cock's spur, 

 and anthos, a flower ; referring to the shape of 

 the flower. Nat. Ord. Labiates. 



Green-house shrubs and herbaceous plants, 

 closely allied to Coleus. Natives of Africa, 

 South America, and Asia. They all have 

 purple flowers, produced in terminal and 

 axillary racemes, but being of little beauty 

 or interest, they are rarely cultivated. 



Plectri'tis. From plectron, a cock's spur; in 

 reference to the flowers being gibbous in front. 

 Nat. Ord. Valerianacece. 



A genus of Californian and Chilian annuals, 

 with pink flowers in dense capitate cymes. 

 They require the same treatment as other 

 hardy annuals. Syn. Valerianella. 



Plectro'nia. From plectron, a cock's spur; in 

 allusion to the large spines which are to be 

 found on some of the species. Nat. Ord. 

 RubiacecB. 



A large genus of ornamental trees or shrubs, 

 sometimes climbing, natives of tropical Asia, 

 Africa, Australia and the Pacific Islands. 

 Few of the species have been introduced, and 

 are of but little interest, horticulturally. Syns. 

 Canthium, Mitrastigma, Phallaria, etc. 



Plee'a. Named after 2)?eia«, the seven stars; in 

 reference to the disposition of the flowers. 

 Nat. Ord. Liliacece. 



P. tenuifolia, the only species, is a hardy 

 perennial plant with knotted-rush-like stems 

 or rhizomes and greenish-white flowers. It is 

 a native of the Southern United States, and is 

 increased freely by seeds. 



Ple'ione. A mythological name. Nat. Ord. 

 Orchiclacem. 



A small genus of dwarf epiphytal Orchids, 

 formerly classed with Coelogyne. They are 

 found growing in high altitudes in the moun- 

 tains of northern and northeastern India. 

 They are remarkable for their dwarf habit 

 and richly-colored flowers. The flowers are 

 produced in autumn or early winter, after a 

 period of rest, and immediately precede the 

 new growth. They are of easy culture, 

 requiring a house of moderate temperature, 

 and alternate seasons of growth and rest. 

 Propagated by division. Introduced in 1864. 



Plenus. Pleno. Double, as in double flowers. 



Pleope'ltis. From pleos, full, and pelte, a shield ; 

 referring to the covering of the spores or 

 seed-cases. Nat. Ord. Polypodiacem. 



An interesting genus of tropical ferns in- 

 habiting some portions of South America and 

 the South Pacific Islands. P. Xiphias is a 

 beautiful plant for the green-house. It is of 

 considerable size, and well furnished with 

 sori; firm, but not leathery in texture, and 

 arched and somewhat undulated at the edge, 

 which is otherwise entire ; the venation is 

 strongly marked and closely reticulated. This 

 genus is now included under Polypodium by 

 some botanists. 



Plero'ma. From pleroma, fullness ; referring 

 to the cells of the seed-vessel. Nat. Ord. 

 Melastomacece. 



PLO 



A small genus of handsome green-house 

 evergreen shrubs from Brazil. They are free 

 flowering and of easy culture. A rich soil and 

 liberal watering during the summer are essen- 

 tial, that the new growth may be strong ; they 

 will then produce their clusters of purple 

 flowers freely in autumn and winter. P. ele- 

 gans is one of the best known species, and 

 bears beautiful flowers of a rich purple color. 

 P. macranthum floribundum is also a very free 

 flowering species, producing its large violet- 

 blue flowers in great profusion on quite young 

 plants. They were first introduced in 1821, 

 and are increased by cuttings. 



Pleurisy Root. A popular name of Asclepias 

 tuberosa, from its supposed medicinal quali- 

 ties. 



Pleuro'gyne. From pleur on, a side, and gyne, 

 the female organ ; referring to the stigmas 

 issuing from the side of the seed-vessel. Nat. 

 Ord. Gentianacem. 



P. rotata, the only cultivated species, is a 

 low growing hardy annual from Siberia. 



Pleurope'talum. From pleuron, a side, and 

 petalon, a petal; in allusion to the shape of 

 the corolla. Nat. Ord. Amaranthacc(B. 



A small genus of slightly-branched glabrous 

 shrubs, natives of Mexico, Ecuador and the 

 Galapagos Islands. P. Costaricense, the only 

 species yet introduced, is a small evergreen 

 shrub with green branches. It was introduced 

 from Central America in 1883, but is rarely 

 found in cultivation. 



Pleurotha'llis. From pleuron, a side, and thallo, 

 to flower: in allusion to the one-sided dispo- 

 sition of the flowers of some of the species. 

 Nat. Ord. Orchidacem. 



This is one of the most extensive genus of 

 Orchids, comprising nearly three hundred 

 species, all epiphytes, and natives of the West 

 Indies and South America. Though interest- 

 ing botanically, only a few species, such as P. 

 omata, P. scapfia, P. tridentata, and P. Burber- 

 iami, have sufficient merit to warrant their 

 introduction into the Orchid house. 



Plicate. Plaited or folded together lengthwise, 

 like a closed fan. 



Plo'cama. From plocamos, bent hairs ; alluding 

 to the pendulous branches. Nat. Ord. Rubi- 

 acecB. 



P. pendula, the only described species, is an 

 erect shrub with very slender, pendulous 

 branches. The flowers are white, small and 

 terminal. It was introduced from the Canary 

 Islands in 1772, and is readily increased by 

 cuttings. 



Plocoste'mma. From plokos, curled, and 

 stemma, a crown ; referring to the crown of 

 the stamens. Nat. Ord. Asclepiadacem. 



A small genus of green-house evergreen 

 twiners, allied to Hoya, and requiring the 

 same general treatment. They inhabit the 

 forests of Borneo and Java. Introduced in 

 1858. 



Ploughman's Spikenard. Baccharis halimi- 

 folia. 



Plowing. Many gardeners yet ignore the plow 

 in the garden, even where it is perfectly prac- 

 ticable to use it. We have used the plow and 

 harrow for pulverizing on every foot that it 

 was possible to use them in, in all our opera- 

 tions in the ground, whether for fruit, flow- 



