AN ENCYCLOPAEDIA OF HORTICULTURE. 



255 



PTJYA (the native name of the plant in Chili). STN. 

 Povrretia. OKD. BromeliacecB. A. genus (eight or ten 

 species) of stove or greenhouse, perennial herbs, natives 

 of Chili and Peru. Flowers showy, blue, yellow, or white, 

 solitary, disposed in a simple or pyramidal branched, 

 terminal raceme ; sepals free, oblong or lanceolate, loosely 

 imbricated; petals free, connivent in a tube at the base, 

 spreading above, rather broad. Leaves either at the 

 base or tip of the stem, clustered, spiny-serrate. The 

 two species here described probably the only ones in 

 cultivation thrive in a compost of loam and peat. 

 Propagation is easily effected by suckers, or by seeds 

 when procurable. 



P. Altensteinii (Altenstein's). A synonym of Piteairnia 



AMtmtteinii. 

 P. cau-nlea (blue*. A synonym of P. Wkytei. 



P. gigas (giant). JL white or rose-coloured, disposed in erect 

 spikes, from 18ft to 30ft in height ' 

 late, hoary, spiny-toothed, mealy-white 



it L tufted, linear-lanceo- 

 New Grenada, 



(sulphur-coloured). A synonym of Piteairnia 



1. An extraordinary species. fR- H. 1881, 74 ; Gn., May 6, 

 1882.) It is very uncertain to what genus this plant really 

 belongs, as the flowers have not been seen by any specialist 

 It has the foliage of an Agave. 

 P. grandlflora (large-flowered). A synonym of Piteairnia /- 



P. heterophylla (variable-leaved). A synonym of Piteairnia 



heterophyUa. 

 P. longifolia (long-leavedX A synonym of Piteairnia hetero- 



il. ..j. 

 P. maidifolia (Indian Corn-leaved). A synonym of Piteairnia 



maidi/olia. 

 P. sulpha 



Wendlandi. 



P. virescens (greenish). A synonym of Piteairnia vireteens. 

 P. Warcewiczii (Warcewicz's). A synonym of Piteairnia 



atrorubeng. 

 P. Whytei (Whyte'sX JL of a peculiar metallic greenish. 



blue colour, with bright orange anthers, disposed in a large, 



pyramidal panicle, on a tall scape. Autumn. L tufted, 



crowded, recurved, elongately subulate, remotely spinescent. 



A. 3ft Chili, 1867. A handsome plant, quite hardy in the 



South of England. (B. M. 5732.) SYK. P. ecemlea. 



PYCNIDIA. Small bodies, very like perithecia (see 

 Perithecium) in general appearance and form, only 

 they are usually smaller, paler, and thinner walled; and 

 the spores in them, instead of being inclosed in asci, 

 are situated, singly or in chains, on the tips of small 

 branches of mycelium that arise from the inner surface 



FIG. 329. PHOMA BERBARUX (Pycnidial Stage of Pleotpora kerba- 

 rum) a, Pycnidia in transverse section, x 20, one opened ; 

 6, Conidia still on the Stalks, x 400; c, Conidia free after 

 falling off the Stalks, x 400. 



of the wall of the Pycnidinm (see Pig. 329). The spores 

 are called stylospores, because of being produced at the 

 tips of these slender, rod-like branches, like a stylus, or 

 pen. A reference to Fleospora, of which Phoma is a 

 Pycnidial form, will help to render clearer the relation 

 of this form of fruit to the perithecia. 



FYCNODORIA. Included under Pteris (which see). 



PTCNOPTEBIS. Included under Nephrodium. 



PYCNOSTACHYS (from pyknot, dense, and stachys, 

 a spike ; referring to the dense flower-spikes). Snr. 

 Echinostachys. OED. Labiate. A small genus (six species) 

 of erect-growing, stove, annual or perennial herbs, natives 

 of tropical or sub-tropical Africa and Madagascar. 

 Flowers in whorls, which are disposed in dense, terminal 

 spikes; corolla blue, with an exserted, detracted tube, 

 two-lipped, the upper lip four-toothed, the lower entire 

 and concave ; calyx ovoid-campanulate, equal, with five 



Pycnostachys continued. 



subulate- spinose teeth. Nutlets almost round, smooth. 

 Leaves stalked, linear - lanceolate to broadly ovate, 

 coarsely toothed. Only two species have been intro- 

 duced to our gardens. For culture, see Ocimum. 



P. casrulea (blue). JL, corolla blue; calyx sessile; spike from 

 lin. to 2in. long. August. L sessile, oblong or linear-lanceolate, 

 2in. to Sin. long, acute, slender, deeply serrated, entire and 

 narrowed at base, glandulose beneath. Stem over 1ft high, 

 tetragonal. Madagascar, 1825. Annual. (H. E. F. 202.) 



P. nrttciiblia (Nettle-leaved). JL blue; upper lip of corolla 

 erect, with four incurved lobes ; lower one concave ; spike ter- 

 minal, ovate, acuminate, large, thvrse like. August L ovate, 

 acuminate, truncate or very obtuse at base, sub-cuneate, long- 

 stalked, deeply serrated, Pubescent beneath. A. 3ft Africa, 

 1862. Perennial. (B. M. 5365.) 



PYGJERA BUCEFHALA. See Buff-tip Moth. 



FYGMJEUS. Pigmy; dwarf. 



PYXNOS. This term, used in Greek compounds, 

 signifies thick, close, dense, compact ; e.g., Pymocephalus, 

 thick-headed. 



Jf JCHACANTHA. See Cratseg-os Pyracantha. 



PYRAilS (Hypena) ROSTRALJS (Hop Snout 

 Moth). This insect is common in the southern districts 

 of England, where the larvae feed on the leaves of the 

 Hop, frequently doing a great deal of harm to them. 

 The moths, when at rest, have the wings folded hori- 

 zontally, and assume the form of the Greek letter delta 

 (A)- They have long palpi, projecting forwards, and 

 the group may be recognised by this peculiarity, whence 

 they are called Snout Moths. The front wings are 

 greyish-brown, darker towards the base, paler along the 

 front margin and across the terminal half of the wing, 

 and a dark line runs from the tip, diverging from the 

 rear margin. The hind wings are uniform brownish. 

 The spread of wings is a little over lin. The larvse are 

 rather slender, tapering in front, pale green, with narrow, 

 white lines lengthwise ; they have six true legs and eight 

 prolegs or claspers. When full-fed, they spin slight 

 cocoons in leaves drawn a little together, and there 

 become pupse. 



Remedies. Hand - picking the larvse, and the leaves 

 inclosing pupae, and burning all surface rubbish with 

 the pupae in it, is the most effectual remedy. Beating 

 the Hops (taking care not to injure the plants) and 

 jarring the Hop-stakes, so as to cause the larvse to fall 

 on to sheets, is efficacious; the larvae being afterwards 

 burnt. Syringing the plants with any of the usual 

 insecticides, by means of a garden engine, is also of 

 use. 



PYRAMIDAL. Pyramid-shaped; more frequently 

 used, however, to denote conical; e.g., a Carrot. 



PYRENA. The stone caused by the hardening of 

 the endocarp in drupaceous fruits. 



PYRENOMYCETES (from pyren, a kernel or 

 stone of fruit, and myket, a Fungus). A very large 

 group of Fungi, so named because they produce, in 

 the processes of reproduction, small, hard, dark bodies 

 (perithecia and pycnidia), in which certain forms of 

 spores are protected. The Pyrenomycetes form one of 

 three families, into which a very large order of Fungi, 

 called Ascomycetet, is divided. This order is charac- 

 terised by the mode of origin of a form of spore, re- 

 garded as the most highly developed of the various kinds 

 produced in them. These spores are produced from a 

 portion of the protoplasm, or living substance, contained 

 in certain long, cylindrical, thin-walled cells, called asci. 

 In each ascus (see Fig. 330) there are usually eight 

 spores formed, but the number varies, in different Fungi, 

 from two to an indefinite number in each, though con- 

 stant in each species. In most Ascomycetous Fungi, the 

 asci grow crowded together, either alone or intermixed 

 with slender filaments (paraphyses) (see Fig. 330) ; and, 



