146 Sensitive Fern 
pinnate or pinnate, above successively less deeply pinnatifid, 
gradually or abruptly narrowing to the undulate or sinuate apex: 
segments two to thirteen pairs, basal or second pair longest, 
connected by a costal-wing or the lowermost distinct, lanceolate 
or oblong-lanceolate, often narrowing both ways, the lower, 
especially, narrowed at base, very minutely serrulate, the upper- 
most otherwise entire or undulate, the lower more or less sinuate 
or, especially the lowermost, deeply sinuous-pinnatifid; the lobes 
oblique, obtuse or a few subacute: apices obtuse or subacute: 
rachis and midribs prominent beneath, smooth or bearing a 
few minute, pale-brown, ovate or lanceolate, acuminate, ciliate 
scales: surfaces glabrous otherwise, the upper grass-green; the 
lower paler, slightly glaucescent: texture herbaceous. 
Blades of sporophylls contracted, oblong, secund, bipinnate; 
apex pinnate: pinne bent backward and upward, appressed, 
alternate or opposite, short-stalked or the uppermost sessile: 
pinnules small, dark green, fleshy or cartilaginous, subglobose, 
alternate or opposite, sessile or subsessile, reflexed, pinnatifid: 
segments four to six, slender, oblong or deltoid, recurved and 
connivent over sporangia, finally spreading apart, inferior basal 
segment of pinnule often dichotomous: rachis when dried more 
or less angled or grooved obscurely or partly subterete, glabrous 
or sparingly chaffy as in sterile leaves. 
Venation of sterile leaves conspicuous, pinnate, anastomose: 
marginal veinlets largely free, simple or once forked: paracostal 
areole parallel or subparallel to costa, elongate, those next rachis 
giving rise successively at ends to midribs of segments, those 
next midribs to midveins of segments’ lobes, in very narrow parts 
of costal-wing contracted to vanishing point or veinlets forming 
their outer edges alone visible, as fibres coherent with rachis: 
