PTERIDIUM 



sporangia borne on a marginal line-like receptacle as in- 

 Pteris (Pig. 2011) and covered with a marginal indu- 

 sium, but with an additional membranous indusium 

 within the receptacle. Commonly known as Pteris. 



aquiUnum, Kuhn. Lvs. scat- 

 tered from an underground rhi- 

 zome, 2-9 ft. high, temately com- 

 pound. Field and waste places in 

 some of its forms throughout the 

 world. L. M. Underwood. 



PTERIS 



1463 



2011 



iting pinnule 

 ot common brake.— 

 Pteridium aauilinum. 

 Natural size. 



FT£BIS (Greek name for s 

 fern, from a word meaning wing; 

 alluding to the prevalence of pin 

 nate forms). Polypodidceie. A 

 large genus of widely distributed ferns with the spor- 

 angia borne on a marginal line-like receptacle that con- 

 nects the free ends ot the veins, and with the more or 

 less altered margin of the leaf rolled over to form a con 

 tinuous indusium. Many of the forms are among the 

 commonest species of ferns in the trade and are quite 

 generally used for table decoration. For culture see 



tending to theapices.which are sharply serrulate. China 

 andJapan. — Many monstrous aii<l distorted forms appear 

 in cult., giving rise to such varietal names as angustata, 

 criattlta, cristata nlina compActa, cristata variegita, 

 dinsa, Gilbertii, OuvrArdi (P. Ouvrardi, Hort.), voluta, 

 etc., but these cannot be regarded as true varieties in 

 any scientific sense. 



4. ensifdrmis, Burm. Lvs. of 2 sorts, the sterile with 

 elliptic or elliptic-lanceolate segments, the lower pinnae 

 5-7-parted, the upper gradually simpler; sporophylls 

 similar but taller and with longer and much narrower 

 divisions. India to Polynesia; often confused with the 

 preceding species, as both are more or less common in 

 cult. Var. Victdrise (P. Virldrup, Hort.) is a garden va- 

 riety with leaves variegated with white. 



5. insequalis, Baker. Lvs. ovate - deltoid, 18-24 in. 

 long, 10-15 in. wide, with 4-5 pairs of pinnate or pinnati- 

 fld pinnffi followed by 2-:j pairs of broadly linear simple 

 ones and ending in a long, terminal irregularly pin 

 natifld portion, divisions of the lower sides i)t the pin 

 nsB uniformly much longer and largei tli m th( upper 

 ones China and Japan 



upplementai-j list 



dinntoides, s 

 iigustata, 3. 



leptophylla. 13. 



/Fiea, 7. longlfolia, 1. 



ist'i. 0. magnifica, 2. 



irit;i, 11. major, 2. 



tic.i, 2. maxima. 11. 



ne„sis. s. L, Mayii. 2. 



lata. 3. 11. nemoralix. 11. 



sa, 3. nobilis, 2. 



iformis, 4. Ouvrardi, 3. 



%nifolia, s. L. palmata. s. L. 



bertii, 3. plnmnsa. s, L. 



taXa, s. L. quadriaurita, 7. 



k. Veins free throughout. 



B. Jyvs. simply pinnate^ the lowet 



pinnw not divided 



BB. Lvs. simply pinnate, but tkt 

 lower pinnoe forked 



BBB. Lvs. withlowestpinnm pinnate 



BBBB. Lvs. with lowest pinnm bipiu 

 natifid. 

 c. Lowest pinn(e enlarged .... 



seaberula 10 

 semipinnati 

 semilata 3 

 Sieholdti s I 



CO. Lowest pinnce not enlarged 

 AA. Veins free, except for a single lot 

 arch next the midvein 



2 Cretica 



S semilata 



4 ensiformis 



5 msequahs 



b semipmnata 



7 quadnaunta 



8 heterophylla 



9 tremula 

 10 Bcaberula 



13 leptophylla 



1. longifdlia, Linn. Lvs. 1-2 ft. long, 4-9 in. wide, 

 lanceolate, often narrowed below; pinnae 20-30 on each 

 side, linear, entire. Tropical regions all around the 

 world, extending to southern Florida. Var. M4riesii, 

 Hort. Fronds shorter and pinnules straighter, the plant 

 keeping closer to the pot; a good horticultural form. 



2. Crfitica, Linn. Lvs. 6-12 in. long, on slender, straw- 

 colored stalks, consisting of a terminal pinna and 2-6 

 opposite sessile pairs, the upper often decurrent, the 

 lower pairs cleft nearly to the base into 2 or 3 pinnules. 

 Quite generally distributed in tropical regions, extend- 

 ing to central Florida. Many varieties are in cult., of 

 which var. albo-line^ta, Hort. (Pig. 2012), is one of the 

 finest, with broader pinnae and a broad, central, whitish 

 band. Var. mijor and var. nbbilis are larger horticul- 

 tural forms, and var. magnifica and var. Hityii {P. 

 MAyii) are still more developed. 



3. semdita, Linn. f. Lvs. 3-12 in. long, on slender 

 brownish stalks, consisting of a terminal pinna and 5-6 

 pairs of lateral ones, the upper ones decurrent and the 

 lower forked into 2 or 3 branches or with second branch 

 above the basal one ; pinnae narrow, the indusium not ex- 



-Var. Bailsei, 



JOIO Ptelea trifoliata the Hop Tree, in iruit (X %) 



6 semipinnita, Lmn Lvs 12-18 in long, the upper 

 portion simply pinnate with decurrent pmnae, the 4 or 

 more lowest pinnatifid on the lower side, the upper side 

 of the secondary rachises bordered by a narrow 1 

 India, China, .Japan and the East Indii " 

 {P. Baiisei, Hort.) is a garden form. 



7. quadriaurita, Retz. Lvs. up to 2-3 ft. long, on 

 strong, pale stalks, with a terminal central pinna cut 

 down to the rachis into numerous linear-oblong lobes, 

 and below this several similar pinnae on each side, the 

 lowest of which are usually again compound with simi- 

 lar but smaller ones branching from the lower side at 

 base. All tropical regions.— Var. argyraea {P.argyrcea, 

 Moore) is a form with a white band down the centers 

 of the pinnte. Var. tricolor ( P. tricolor, Linden) is simi- 

 lar but has a tinge of red in addition. 



8. heterophj'lla, Linn. Lvs. 6-8 in. long, on pale stalks, 

 of 2 sorts ; sterile lvs. elliptic, deeply incised ; sporophylls 

 narrowly linear-elliptic, with broad indusia and sterile 

 apices ending in 2-3 teeth; both sorts bipinnate in the 

 lower portions. West Indies to Brazil. Sometimes 

 referred to a distinct genus, Anopteris. Var. intemilta 

 {P. internAta, Moore) is a garden variety with smaller 

 sporophylls and broader segments. 



