﻿no 10. LYGODIUM. 



§ 1. EULYGODIUM. 



a. Barren pinnae forked or more commonly digitate or dichotomous. 

 1. Fertile segments not or hardly narrowed. 



f. Pinnae once forked. (1) L. semihastatum. 



•J-.f. Pinnae at least 2 X forked. (2) L. Teysmannii. 



±.1. Fertile segments conspicuously narrowed or contracted. 



2. Spikes + close, in continuous, short or long rows along the margin 

 of the segments. 



3. Ultimate segments bordered by a marginal strand; the gemmi- 



form apex of the rachis clothed with brownish hairs. Spores 



verruculose. (3) L- circinatum. 



3.3. Ultimate segments ivithout marginal strand; the hairs of the 



gemmiform apex blackish. Spores coarsely tuberculale. 



(4) L. digitatum. 

 3.2. Spikes in groups of 3 — 6 on the lobes of the segments. (S) L. trifurcatum. 

 a.a. Barren pinnae pinnate, the pinnulae simple or variously divided. 

 h. All the pinnulae regularly pectinato-pinnatifid throughout. 



(6) L. polystachyum. 

 b.b. Pinnulae simple, or the lower ones forked, hastate, subpalmate or pinnate. 

 c. Pinnulae articulate at the base, or the ultimate petioles distinctly 

 nodose at the apex. 



-{•. Pinnulae oblong, simple, 2 — S^j^ c.M. long. Spores reticulate. 



(7) L. scandens. 

 •^.'i'. Pinnulae linear-oblong or lanceolate, S^j^ — dl c.M, long, the 

 lower fertile ones simple or pinnate. Spores verruculose. 



(8) L. salicifolium. 

 c.c. Pinnulae not articulate, nor the ultimate petioles distinctly nodose 

 at the apex. 



d. Pinnulae i — 2-juga1e, the lower ones simple. (9) L. altum. 

 d.d. Pinnulae 2 — 7-jugate, the lower ones mostly hastate, sub- 

 palmate or pinnate. 



e. Barren pinnae rather long, the segments serrulate. Fertile seg- 

 ments often narrower, but not contracted. (10) L. flexuosum. 

 c.e. Barren pinnae rather short, the segments coarsely crenale. 

 Fertile segments contracted and deeply incised. 



(11) L. japonicum. 



