PTERIDIUM 



PTERIS 



1463 



sporangia borne on a marginal line-like receptacle as in 

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

 sium, but with an additional membranous indusiura 

 within the receptacle. Commonly known as Pteris. 



aquilinum, Kuhn. Lvs. scat- 

 tered from an underground rlii- 

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

 pound. Field and waste places in 

 some of its forms thi'oughout the 

 world. L. M. Underwood. 



2011. Fruiting pinnule 

 of common brake. — 

 Pteridium aauilinum. 



Natural size. 



PTfiRIS (Greek name for a 

 fern, from a word meaning wing; 

 alluding to the prevalence of pin- 

 nate forms). Poltjpodictcece. A 

 large genus of widely distributed ferns with the spor- 

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

 nects the free ends of 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 

 J>^ern. 



INDEX. 



S. L. refers to supplementary list. 



adiatitoides, S. i 

 albo-Iineata, 2. 

 angustata, 3. 

 aqxdlina, s. L. 

 argyrsea, 7. 

 Bausei, 6. 

 blaurita, 11. 

 Cretica, 2. 

 Ohinensis, s. l. 

 cristata, 3, 11. 

 densa, 3. 

 ensiformis, 4. 

 geranifolia, S. l 

 Gilbertii, 3. 

 hastata, s. l. 



heterophylla, 8. 

 inequalis, 5. 

 internata, 8. 

 leptophylla, 13. 

 longifolia, 1. 

 magniflea, 2. 

 major, 2. 

 maxima, 11. 

 Mayii, 2. 

 nemoralis, 11. 

 nobilis, 2. 

 Ouvrardl, 3. 

 palmata, s. L. 

 plumosa, S. L. 

 quadriaurita, 7. 



regina, s. L. 

 scaberula, 10. 

 semipinnata, 6. 

 serrulata, 3. 

 Sieboldii, s. L. 

 Smithiana, 9 . 

 Smithii, 9. 

 Suorardii, S. L. 

 tremula, 9. 

 tricolor, 7. 

 variegata, 9. 

 Victorije, 4. 

 voluta, 3. 

 WaUiehiana, 12. 

 Wimsetti, s. L. 



A. Veins free throughout. 



B. Lvs. simplj/ pinnate, the lower 



pinme not diritled 1. longifolia 



BB. Lvs. simplu pinnate, hut the 



lower pinnce forked 2, 



3 



BBB. Lvs. with lowest pinnce pinnate. 



3BBB. Lvs. with lowest pinnce bipin- 

 natifid. 

 C. Lowest pinnce enlarged 



Cretica 



serrulata 



ensiformis 



inaequalis 



semipinnata 



quadriaurita 

 heterophylla 

 tremula 

 scaberula 



9 

 CC. Lowest pinnce not enlarged ..10 

 Veins free, except for a single low 



arch next the midvein 11 



12, 



Veins uniting, forming copious 

 meshes . . , 13. leptophylla 



biaurita 

 Wallicliiana 



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

 lanceolate, often narrowed below; pinn^ 20-30 on each 

 side, linear, entire. Tropical regions all around the 

 world, extending to southern Florida. Var. Mariesii, 

 Hort. Fronds shorter and pinnules straighter, the plant 

 keeping closer to the pot ; a good horticultural form. 



2. Cr6tica, 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-lineS,ta, Hort. (Fig. 2012), is one of the 

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

 band. Var. mijor and var. n6bilis are larger horticul- 

 tural forms, and var. magnlfica and var. M^yii (P. 

 Mdyii) are still more developed. 



3. serrulata, 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; pinnee narrow, the indusium not ex- 



tending to the apices, which are sharply serrulate. China 

 and.Japan. — Many monstrous and distorted forms appear 

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

 crist&ta, cristata nana compacta, cristata variegata, 

 d6nsa, Gilbertii, Ouvrdrdi {P. Onvrardi, Hort.), voliita, 

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

 any scientific sense. 



4. ensif6rmis, 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. Victdriae {P. Victoria', Hort.) is a garden va- 

 riety with leaves variegated with white. 



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

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

 fld pinnae followed by 2-3 pairs of broadly linear simple 

 ones and ending in a long, terminal, irregularly pin- 

 natifid portion; divisions of the lower sides of the pin- 

 nae uniformly miich longer and larger than the upper 

 ones. China and Japan. 



2010. Ptelea trifoliata. the Hop Tree, in fruit (Xi4). 



6. semipinnata, Linn. Lvs. 12-18 in. long, the upper 

 portion simply pinnate with decurrent pinnae, the 4 or 

 more lowest pinnatifid on the lower side, the upper side 

 of the secondary rachises bordered by a narrow lamina. 

 India, China, Japan and the East Indies. — Var. Bailsei, 

 (P. Bausei, 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.argyraa, 

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

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

 lar but has a tinge of red in addition. 



8. heterophylla, 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. internata 

 (P. internata, Moore) is a garden variety with smaller 

 sporophylls and broader segments. 



