Some New American Species of Dryopteris 79 



Dryopteris (Lastrea) Jimenezii Maxon & C. Chr., sp. 



nov. 



Rhizome obliquely erect, scaly at the top. Stipites 

 fasciculate, 3 or 4 together, 5-10 cm. long, rigid, chan- 

 nelled, without hairs, but in the lower part densely 

 chaffy by castaneous, glossy, entire, ovate-acuminate 

 scales, these up to 1 cm. long and easily deciduous. 

 Lamina lanceolate, 30-50 cm. long, 10-15 cm. broad 

 near the middle, upward gradually tapering into the 

 pinnatifid apex, downward rather suddenly narrowed 

 with 4 or 5 pairs of auriculiform pinnae, dark green, 

 thinly membranous or firmly herbaceous, bipinnatifid. 

 Rachis slender, slightly pubescent, especially above, by 

 short, unicellular, appressed hairs. Pinnae alternate or 

 suboppositc at distances of 2-3 cm., sessile, acuminate, 

 the middle ones 7-8 cm. long, 1.5-1.8 cm. broad, their 

 midrib on both sides slightly hairy like the rachis, the 

 surfaces with some few very inconspicuous appressed 

 hairs (especially on the veins), pinnately incised to a 

 narrow (1 mm.) costal wing. Segments about 1 cm. 

 long, 2-3 mm. broad, obtuse or subacute, patent or a 



little oblique, considerably widened at the base and 



separated by broad but acute sinus.-, their margin- 

 regularlv and obtusely toothed or crenate; basal seg- 

 ments equal to the others or a little shorter. Veins 

 simple, remarkablv distant and distinct, about 6 to each 

 side, nearlv at right angles to the costula, running into 

 the teeth. Sori small, supramedial, exindusiate. bpor- 

 angia few, early deciduous, glabrous. 



Costa Rica: San Jeronimo, altitude 1500 meters, 



collected by C. W< 



1910; Herb. Oton 



•Jimenez no. 567 (U. S. Nat, Herb. no. 861635, type). 



This new species is certainly a close ally of D. svpran- 

 tem Christ and D. lablaziensis Christ, both from Cos a 

 Rica, resembling them in the presence of num< ? r ° 

 scales on the stipes below, a character rather rare witn.n 





