PTELEA 



PTERIS 



2851 



exstipulate, 3-5-foliolate; Ifts. entire or crenulate, 

 punctate with pellucid dots: fls. small, polygamous, in 

 terminal corymbs; lobes of the minute calyx, petals 

 and stamens 4-5; ovary flattened, 2-celled, with short 

 style: fr. a 2-seeded, indehiscent, small, flattened nut, 

 furnished usually with a broad thin wing. Usually 5 

 to 7 species distributed from Lake Ont. to Fla. and N. 



3250. Ptelea aptera. 



Mex. are recognized, but recently about 60 species have 

 been distinguished by Greene. Bark and foliage are 

 sometimes used medicinally and emit (as well as the 

 frs.) when bruised, a strong, pungent odor resembling 

 somewhat that of the hop, for which the frs. are said 

 to have been used as a substitute hence the name hop 

 tree. 



The hop trees are ornamental shrubs or small round- 

 headed trees with long-petioled leaves and greenish 

 white flowers, followed by flattened usually broadly 

 winged and nearly orbicular fruits. The one species 

 chiefly cultivated is hardy North if it proves tender, as 

 it sometimes does, it is probably raised from south- 

 ern seed and is a small round-headed rather loosely 

 branched tree with glossy green foliage, adorned in fall 

 with numerous clusters of light green fruits which form 

 a pleasing contrast with the dark green foliage and 

 remain on the branches for some time after the leaves 

 have fallen. It thrives best in a porous moderately 

 moist soil and prefers a somewhat shaded position. 

 Propagation is by seeds sown in fall; the varieties by 

 layers or by grafting in spring under glass or budding 

 in summer on seedlings of the type. 



trifoliate, Linn. HOP TREE. WATER ASH. Fig. 3249. 

 Shrub or small round-headed tree, attaining 25 ft. : Ifts. 

 3, sessile, ovate to elliptic-oblong, narrowed at both 

 ends, sometimes acuminate, the lateral ones unequal at 

 the base, crenulate or entire, dark green and lustrous 

 above, pale below, glabrous or pubescent when young, 

 3-5 in. long: fls. ^-^in. across; filaments villous be- 

 low: fr. about 1 in. long, broadly winged. June. Ont. 

 and X. Y. to Fla., west to Minn., and sometimes escaped 

 from cult, elsewhere. S.S. 1:33, 34. G.C. III. 16:375. 

 Several varieties are in cult., of which var. aurea, 

 Behnsch (P. aurea, Hort.), the GOLDEN HOP TREE, with 

 yellow foliage, is the best known. Var. glauca, Kirchn. 

 Lvs. grayish green, pubescent when young. Yar. mollis, 

 Torr. & Gray (P. mollis, Curtis. P. tomentdsa, Raf.). 



Branchlets, infl., and Ivs. beneath pubescent or tomen- 

 tose. N. C. and Fla. to Ariz. More tender than the 

 northern glabrous form and rarely cult. 



aptera, Parry. Fig. 3250. Shrub, to 15 ft.: Ifts. 3, 

 sessile, the terminal one elliptic-obovate or obovate, 

 y?-%in. long, the lateral ones smaller, obscurely 

 crenulate, pubescent: clusters few-fld.: fr. broadly 

 ovate, turgid, wingless or nearly so, "%- 

 Hin. long. Low. Calif. G.F. 3:333 

 (adapted in Fig. 3250). Possibly cult, 

 in Calif.; not hardy North. 



ALFRED REHDER. 



PTERIDIUM (Greek, with the form of 

 Pteris'). Polypodidces. Large ternately 

 divided ferns commonly known as 

 BRACKEN or BRAKES, with the sporangia 

 borne on a marginal line-like receptacle 

 as in Pteris (Fig. 3251) and covered with 

 a marginal indusium, but with an addi- 

 tional membranous indusium within the 

 receptacle. Commonly known as Pteris. 



aquilinum, Kuhn. Lvs. scattered from 

 an underground rhizome, 2-9 ft. high, 

 ternately compound. Fields and waste 

 places, in some of its forms throughout the 

 world. In some parts of the world it is 

 used as food, in New Zeal, especially. It 

 is counted a weed in the western states and 

 a Farmers' Bulletin mentions methods of 

 eradicating it. L. M. UNDERWOOD. 



PTERTOOPHtLLUM (Greek, fern leaf, 

 referring to the pinnate Ivs.). Papaveraceae. 

 Perennial acaulescent herbs with a rather 

 thick praemprse rhizome: roots fibrous: 

 Ivs. all radical, petiolate, pectinate-pin- 

 natifid: scapes naked, longer than the Ivs. 

 with a simple or at base subramose many-fld. raceme; 

 sepals 2, deciduous, very short; petals 4, deciduous, 

 elliptic-concave; stamens 4, deciduous; ovary orbicu- 

 lar, 1-celled, 2-4-seeded: fr. unknown. One species, 

 Japan, P. rocemosum, Sieb. & Zucc. A small glabrous 

 herb with narrowly obovate Ivs. 4-6 in. long, about 1 

 in. broad: segms. oblong-linear, rounded at the apex: 

 scape slender, 6-9 in. tall, bearing a loose raceme of 

 small white fls. Intro, into botanic 

 gardens abroad; probably not 

 otherwise cult. 



3251. 



Fruiting pinnule of 

 common brake. 

 Pteridium aquilinum. 

 (Natural size.) 



PTERIS (Greek name for a fern, 

 from a word meaning wing; allud- 

 ing to the prevalence of pinnate 

 forms). Polypodiocese. A large 

 genus (60 species) of widely distrib- 

 uted ferns with sporangia borne on 

 a marginal linv.'-like receptacle that 

 connects the free ends of the veins, and with the 

 more or less altered margin of the leaf rolled over to 

 form a continuous indusium. Many of the forms are 

 among the commonest species of ferns in the trade and 

 are very generally used for table decoration, especially 

 as small plants for fern-dishes. For culture, see Fern. 



The common brake, P. oquilina, Linn., is by some 

 authors now referred to a separate genus; see Pteridium, 

 above. 



Pteris probably contains as many cultivated forms as 

 Xephrolepis, but in America at least does not rank with 

 this fern in importance in the trade. As pot-plants for 

 the house, the species cretica and semdata and their 

 varieties will probably succeed as well as most of the 

 nephrolepis forms, and better than some. They are, 

 however, extremely uncommon, except as already noted, 

 as small plants for fern-dishes. Apparently only one 

 dealer in America makes a specialty of growing pteris. 

 His list is given at -the end of this article. 



