316 



HENDERSON'S HANDBOOK OF PLANTS 



PET 



cultivation. P. vulgaris is the Bog Rhubarb, 



or Butter Bur. 

 Petiole. The foot-stalk of a leaf. 

 Petiole. Common. The first and principal 



leaf-stalk in compound leaves. 



Petive'rla. Named after James Petiver, a dis- 

 tinguished botanist of London, 1665-1718. Nat. 

 Ord. Phytolacacece. 



P. Alliar/'M, or Guinea Hen "Weed, the only 

 cultivated species, is an ornamental, slender, 

 erect green-house plant, with an onion-like 

 smell. It is found from Mexico to Brazil, and 

 is seldom seen in cultivation. 



Petrae'a. Linnfeus dedicated this genus to 

 Robert James, Lord Petre, a celebrated patron 

 of botany, who died in 1742. Nat. Ord. Verben- 

 acecB. 



A genus of twining shrubs or small trees, 

 natives of Mexico and South America. P. 

 volubilis and some of the other species are 

 very beautiful flowering climbers. The flowers 

 are large, of a deep violet color, and pro- 

 duced in graceful racemes, and are increased 

 by cuttings in spring. They were first intro- 

 duced in 1834. 



Petraeus, Petrosus. Growing in rocky or stony 



places. 

 Petro'biuni. From petros, a rock, and bio, to 



live, alluding to the habitat of the species. 



Nat. Ord. CompositcB. 

 P. arboreum, the only described species, is 



an ornamental green-house shrub with yellow 



flowers. Introduced from St. Helena in 1816, 



it succeeds well in sandy loam, and is readily 



increased by cuttings. 



Petroca'llis. From petros, a rock, and kalos, 

 beautiful ; the plant adorns the rocks on 

 which it grows. Nat. Ord. CrucifercB. 



P. Pyrenaica, the only species, is a pretty 

 little tufted plant, peculiar to Alpine places in 

 the Pyrenees, and growing in dense patches, 

 like many of the Saxifragas. The stems, an 

 inch or two high, are densely clothed with 

 wedge-shaped, lobed leaves, and terminate in 

 a raceme of rather large, purplish flowers, 

 which are followed by small, oval, swollen, 

 two-celled seed-pods. It is a very interesting 

 plant for a rockery, but must be given but lit- 

 tle soil and the most complete drainage. Syn. 

 Draba. 



Petroco'smea Sinensis. A new genus of Ges- 

 neracece, of which the present species is the 

 only one so far described. It is a beautiful 

 little plant with violet or blue flowers and 

 resembling a Violet in habit. It was found 

 by Dr. Henry (1888) growing on the surface of 

 a rock in the bottom of a small cave near 

 Ichang (China) with the leaves closely pressed 

 against the rock. 



Petro'phila. From petros, a rock, and phileo, 

 to love ; in allusion to the place of growth. 

 Nat. Ord. Proteacece. 



A genus of about twenty-five species of 

 green-house shrubs, natives of Australia, 

 with white or yellow flowers in dense, termi- 

 nal spikes or cones. They are seldom culti- 

 vated except in large conservatories. 



Petroseli'num. A synonym for Apium Petroseli- 

 num, which see. 



Pettigree, or Pettigrue. A common name for 

 Rvscus aculeatus. 



PET 



Pettiwhin. A popular name for Genista Anglica 

 and Ononis arvensis. 



Petu'nga. Peetunga is the name of P. Rox- 

 burghii in Bengal. Nat. Ord. RubiacexjB. 



A small genus of ornamental plant-stove 

 shrubs, natives of eastern Bengal, the Malay 

 Peninsula and the Indian Archipelago. P. 

 Roxburghii, the only cultivated species, is a 

 very ornamental plant, with white flowers; 

 easily increased by cuttings in heat. 



Petu'nia. From petun, Brazilian name for 

 tobacco, to which the Petunia is allied. Nat. 

 Ord. Solanacew. 



A small genus of half-hardy herbaceous per- 

 ennials, all natives of South America, and 

 mostly confined to Brazil. Though coming 

 from a tropical country, where they are 

 strictly perennial, they may be grown as 

 hardy annuals. In the whole range of what 

 ai"e called "bedding plants," there is not an 

 individual that can be said to exceed in gen- 

 eral usefulness the Petunia. They are of the 

 easiest culture, seeding themselves when 

 once planted, growing in any soil that will 

 sustain plant life, and producing the most 

 showy flowers in the greatest profusion. 

 Few, if any, plants have come so rapidly into 

 popular favor, or have been so much improved 

 by hybridization and cultivation. Only a few 

 years ago they were comparatively unknown, 

 and now there is not a garden, either large or 

 small, where they are not grown ; nor are they 

 confined to the garden, as the windows of the 

 workshop and the inunble tenement so cheer- 

 ily testify. P. nyctaginiflora, the common 

 White Petunia, was first introduced into Eng- 

 land from Brazil in 1823. It was but little culti- 

 vated, and only in the green-houses as a peren- 

 nial, until 1830. At this period P. violacea or P. 

 Phoenicia, as it is sometimes called, was intro- 

 duced from Buenos Ayres by a Mr. Tweedie, 

 a botanical collector, who sent seeds of it to 

 the Botanic Garden at Glasgow. It was soon 

 found that it w^ould propagate freely from 

 seed, and in a short time it became widely 

 disseminated. It was figured and sent out 

 first as Salpiglossis integrifolia and Nierem- 

 bergia Phoenicia. From these two species all 

 our garden varieties have been produced. To 

 Isaac Buchanan, of New York, belongs the 

 credit of having first hybridized these species, 

 the result being the magnificent blotched and 

 striped vai'ieties now so extensively culti- 

 vated. His first effort was crowned with the 

 most complete success, the hybrids being as 

 perfectly and distinctly marked as any since 

 produced. These were for a number of years 

 offered in seedsmen's eata]f)gues as "Bucha- 

 nan's Hybrids." Many other splendid sorts 

 have been produced in this country, and 

 among them the "Fringed Petunia," from 

 which the Germans have succeeded in getting 

 a double variety, finely fringed. Many double 

 varieties are now sent out each season, claim- 

 ing special meiit. They are well adapted for 

 green-house culture, but for massing or ex- 

 tended borders, the best marked single varie- 

 ties are far superior, because they produce 

 their flowers in greater abundance. Where a 

 mass of any particular color is desired, it is 

 better to strike cuttings of the favorite kinds 

 in the fall. For the mixed border, the seeds 

 may be sown where wanted to grow ; or, if 

 wanted to flower early, seed may be sown in 



