2864 



PYRACANTHA 



PYROSTEGIA 



the type. M.D.G. 1901:136. Var. paucifldra, Dipp. 

 Of low, dense habit and very thorny: corymbs small: 

 fr. yellowish red. Hardy, and well suited for hedges. 

 Var. leucocarpa, Hort. (Cotonedster Pyracdntha leuco- 

 cdrpa, Hort., var. friicto-dlbo, Hort.), is a form with 

 white or yellowish frs. 



crenulata, Roem. (Cotonedster crenulata, Wenzig. 

 Cratasgus crenulata, Roxbg. P. Rogersidna, Hort.). 

 Closely allied to the preceding: branchlets and petioles 

 rusty-pubescent, glabrous at length: Ivs. narrower, 

 oblong to oblanceolate, obtuse or acutish, more leath- 

 ery, bright green and glossy above, 1-2 in. long: corymbs 

 glabrous: fr. slender-pedicelled, globose, bright orange- 

 red. May, June. Himalayas. B.R. 30:52. R.H. 1913: 

 204 and p. 205. G.M. 58:31. G.C. III. 57, suppl. Feb. 

 20. More tender than the preceding, with handsomer, 

 glossier foliage. Var. yunnanensis, Vilm. More vigor- 

 ous: spines to 2 in. long: Ivs. 2-3 in. long, finely den- 

 ticulate, obtuse: "corymbs more numerous, many-fld.: 

 fr. short-pedicelled, bright coral-red, smaller. Yunnan. 

 R.H. 1913:204. 



AA. Los. beneath and calyx tomentose. 

 angustifolia, Schneid. (Cotonedster angustifolia, 

 Franch.). Shrub with long and slender, spreading and 

 often partly prostrate branches; young branchlets yel- 

 lowish tomentose: Ivs. subcoriaceous, narrow-oblong, 

 obtuse and mucronulate, recurved at the margin, entire 

 or sparingly glandular-serrulate, glabrous, grayish 

 tomentose beneath, %-2J4 in- long: corymbs few-fld., 

 short-stalked; calyx grayish pubescent outside: fr. 

 depressed-globose, Hin. thick, orange-yellow. May, 

 June. S. W. China. B.M. 8345. G.C. III. 36:441. 

 Gn. 67 : 105, p. 24. ALFRED REHDER. 



PYRENACANTHA (Greek, grain, thorn; the inner 

 surface of the husk of the fruit is covered with many 

 blunt prickles). Icacindcese. Climbing shrubs with 

 alternate, hairy, 3-5-nerved, entire, or toothed or 

 lobed Ivs. and fls. in spikes: fls. dio3cious; perianth 4- 

 or rarely 3-5-lobed; ovary superior, 1 -celled, 2-ovuled: 

 drupe compressed, with the mesocarp spinulose-verru- 

 cose within. About 15 species from Trop. and S. Afr. 

 P. malvifolia, Engl. A succulent plant with a fleshy 

 subglobose smooth st. resembling a stone from a dis- 

 tance: branches short or long and scandent: Ivs. kid- 

 ney-shaped, irregularly 3-5-lobed, pilose: fls. small, in 

 spikes; perianth 4-lobed. E. Afr. G.W. 10, p. 354. 



PYRETHRUM (a name used from the time of Dios- 

 cprides, the derivation from the Greek, much fire, refer- 

 ring to the acrid roots). Compdsitse. This name is still 

 commonly used in garden literature and language 

 although the genus has long been reduced to a section 

 of Chrysanthemum. Almost every nursery catalogue 

 offers P. roseum and its numerous varieties, which is 

 referred by botanists to Chrysanthemum coccineum; also 

 P. parthenifolium var. aureum, the golden feather, and 

 P. uliginosum. (See Vol. II, p. 753.) All three of these 

 are rather common in gardens and they are known to 

 most lovers of hardy perennials. 



More recent introductions under the name Pyreth- 

 rum are P. Tchihatchewii, also spelled Tchihatcheffii, 

 the "turfing daisy" (see Chrysanthemum Tchihatchewii, 

 Vol. II, p. 756), and P. leucopiloides, Hausskn., a sub- 

 alpine perennial with silvery white leaves and large 

 yellow flower-heads. Asia Minor. Suitable for the 

 rockery. This last species is not mentioned under 

 Chrysanthemum . 



PYROLA (a diminutive of Pyrus, the pear tree, from 

 some fancied resemblance in the foliage). Pyroldcese. 

 WINTERGREEN. SHIN LEAF. Low and smooth peren- 

 nial herbs with running subterranean shoots; suitable 

 for the native garden though not commonly cultivated. 



Acaulescent or caulescent, with a cluster of roundish 



or elliptical evergreen basal Ivs. and a simple raceme of 

 nodding white, greenish or purplish fls. on an upright 

 more or less scaly-bracted scape: calyx 5-parted, per- 

 sistent; petals 5, concave, deciduous; stamens 10: caps, 

 depressed-globose, 5-lobed, 5-valved. Ten to 15 species, 

 Great Britain to N. Asia and N. Amer. south to Mex. 

 Formerly referred to Ericaceae, but now placed in 

 Pyrolaceae together with Chimaphila and Moneses. 

 The name wintergreen is usually applied to Gaultheria. 

 Pyrolas grow naturally in rather poor sandy uplands 

 and in bogs. Like many members of the heath family, 

 wintergreens are difficult to cultivate and will not suc- 

 ceed in garden soil. In removing them from the woods, 

 care should be taken to secure a large ball of earth. They 

 may then succeed in the shade of evergreens and upon 

 rockeries in peaty soil. The species are scarcely in 

 general cult.; they are offered by dealers in native 

 plants. P. americana is probably more cultivated 

 than the others. 



A. Fls. greenish; style straight. 



secunda, Linn. Height about 6 in.: subcaulescent : 

 Ivs. thin, ovate, crenate, 1-1 H in. long: fls. small, in a 

 1-sided, dense, spike-like raceme. N. Atlantic States 

 to Lab., Rocky Mts. to arctic regions, N. Eu. to Japan. 

 June-Aug. 



AA. Fls. greenish white; style curved downward. 



chlorantha, Swartz. Height 5-10 in.: Ivs. small, 

 orbicular, thick, dull, shorter than the petiole: fls. few; 

 anther-cells with beaked tips. Lab. to Pa., Rocky Mts., 

 north to subarctic regions. June and July. 



elliptica, Nutt. Height 8-10 in. : Ivs. broadly oval or 

 oblong, thin, dull, serrulate, 2-2 3/ in. long, longer than 

 the petiole: loosely 5-10-fld.; calyx-lobes ovate, acute, 

 one-fourth length of the obovate whitish petals. Can- 

 ada to Brit. Col. and through N. Atlantic States to New 

 Mex., Japan. June and July. 



picta, Smith. Height 5-10 in.: Ivs. thick, broadly 

 ovate to spatulate, dull, blotched with white above, 

 pale or purplish beneath, longer than the petioles: 

 calyx-lobes ovate, not one-half length of the greenish 

 white petals. Pacific slope. 



AAA. Fls. white. 



americana, Sweet (P. rotundifplia, Amer. Auth., not 

 Linn.). Height 5-12 in.: Ivs. orbicular, about 2 in. long, 

 thick, shining above, shorter than the petioles: fls. 

 numerous; bracts conspicuous; calyx-lobes lanceolate 

 or oblong-lanceolate, one-third to one-half length of 

 the thick white petals. E. Canada, south to Ga., west 

 to S. D. June-Aug. 



AAAA. Fls. pink or purple. 



asarifolia, Michx. Lvs. transversely broad-elliptic 

 or round-reniform, cordate: fls. %-^in. across, purple; 

 calyx-lobes ovate to ovate-triangular. Que. to Yukon, 

 south to Nova Scotia, N. New England, W. N. Y., N. 

 Mich., and Col.; also in Asia. June-Aug. 



Var. incarniita, Fern. (P. rotundifolia var. uligindsa, 

 Gray), with pink or rose-colored fls. and subcordate to 

 obovate, dull Ivs., occurs in swamps, arctic regions, 

 south to N. New England, Cent. N. Y., Mich., Wis., 

 Col., and Calif.; also Asia. p. TRACY HUBBARD.! 



PYROLfRION: Zephyranthes. 



PYROSTEGIA (Greek, pyr, fire, and siege, root', 

 alluding to the color of the flowers and the shape of its 

 upper lip). Bignonidcese. Ornamental vines cultivated 

 chiefly for their handsome and showy flowers. 



Evergreen shrubs climbing by tendrils: Ivs. 2- or 3- 

 foliolate; tendril filiform, 3-parted: fls. in terminal pani- 

 cles; calyx campanulate or nearly tubular, truncate or 

 dentate; corolla tubular-funnelform, curved, the lobes 

 valvate in bud; stamens exceeding the tube; disk annu- 



