FERNS OF THE MALAY- ASIATIC REGION. 
1 5 
OSMUNDA Linnaeus. 
Sporangia entirely covering very reduced segments which may make 
up certain pi rime, or whole fronds, the fertile pinnse more compound 
than the sterile; fronds pinnate or bipinnate, pinnae and pinnules ar- 
ticulate to raehises. Ten species, one in Brazil, beside the following. 
The three species of the eastern United States all reappear in eastern 
Asia, but are wanting in the western United States. 
Sterile fronds bipinnate ( Eu-Osmunda ) . 
Pinnules not acute at base. 
Pinnules oblong or lanceolate, not adnate 1. O.regalis 
Pinnules almost round, mostly adnate 2. 0. mildel 
Pinnules acute at base 3. 0. lancea 
Sterile fronds deeply bipinnatifid ( Osmundastruji ) . 
Fertile and sterile fronds distinct 4. 0. cinnamomea 
Fertile and sterile pinnules on same frond 5. 0. claytoniana 
Sterile pinnae not deeply pinnatifid (Plenasium) . 
Pinnae narrowly linear 6. 0. bromeliifolia 
Pinnse lanceolate or linear-lanceolate. 
Pinnae with salient teeth 7. O. banksiifolia 
Pinnae with appressed teeth or entire. 
Larger pinnae more than 25 cm long 8. 0. javanica 
Larger pinnse less than 20 cm long 9. 0. vachelii 
1. Osmunda regal is L. 
Stipes tufted, usually more than 30 cm high; frond, excluding stipe 
50 to 120 cm high, 30 cm or more broad, bipinnate, a few apical pinnse 
fertile; pinnae approximately opposite, short-stalked; pinnules subsessile, 
3-5 cm long, about 1 cm broad, the sides parallel, obtuse, unequally trun- 
cate at the base, finely serrulate, subeoriaceous, glabrous; fertile pinnules 
reduced, cylindrical, lobed or pinnate. 
Var. japonica Thunb. (Plate XI.) 
Usually smaller than the typical form, sterile and fertile fronds dis- 
tinct ; the sterile pinnules gradually narrowed upward from a broad base. 
Cosmopolitan, but unknown in the Philippines. Malaya and Australia : the 
variety japonica is the common form from Japan to India. 
2. Osmunda mildei C. Clir. (0. bipinnata Hook.) 
A rather smaller fern than 0. regalis, upper sterile pinnae entire, the 
others with an entire distal segment about 3 cm long and 10 to 14 mm 
broad with rounded apex, lobed below this, and below the lobes bearing 
pinnules 10 to 17 mm long, about 9 mm broad, entire, rounded at both 
ends and adnate to the winged rachis, fertile pinnae typically at base of 
frond, but often found elsewhere, or almost the whole frond fertile. 
Hongkong and adjacent mainland. 
