1. Marsilia.] 9. MARSILIACE^. 



1. MARSILIA, L. 



Small herbs with a slender creeping rhizome terminating in a 3- 

 sided apical cell giving rise to 2 dorsal rows of leaves and a ventral 

 row of roots (adventitious roots are also sometimes developed). 

 Mature leaves 4-f oliolate ; in very young plants there is a cotyledonary 

 leaf followed by simple primordial leaves and sometimes floating leaves. 

 Sporocarps bean-shaped, bilaterally symmetrical, many-celled, finally 

 2-valved, pedicelled. Pedicels branching from the petiole of the leaf 

 or from its base, solitary, or several from one petiole {cp. Ophioglossum), 

 adnate to the base of the sporocarp and forming a raphe (not always 

 apparent) which usually ends in a tooth and often bears a second lower 

 tooth ; its vascular bundle running along the dorsal edge of the sporo- 

 carp gives off lateral nerves into both valves which fork and run to 

 the opposite suture. Mature sporocarps with very firm shell con- 

 sisting of 5 layers. Innermost a cartilaginous band passing round the 

 sutures and from which spring opposite the nerve-forks on both sides 

 the sori. On the valves opening in water this tissue swells up, becomes 

 extruded, and finally rupturing one end, is seen to bear the sori pin- 

 nately arranged along it, each enclosed in a hyaline membrane. Each 

 sporangium with few macrospores and many microspores. 



So far as the herbarium material goes there appears to be but one species of 

 Marsilia in our area. M. quadrifoliata, L., certainly does not occur and probably 

 does not occur anywhere south of the Himalayas. In the following key (from 

 Sudebeck), however, I have given the character for some other Indian species 

 which may possibly occur : 

 T. Several (2-5) sporocarps at the base of the petiole. L. with- 

 out interstitial strips of sclerenchymatous cells :— 



A. Pedicels arising far from the base of the petiole, connate 



for about half their length (quadrifoliafa). 



B. Pedicels arising at the base of the petiole, free or very 



shortly connate with one another : — 



1. Sporocarps strigosely hairy or glabrescent, often ribbed, 



usually margined. L. lobulate . . . .1. minuta (erosa). 



L. entire, larger, sporocarps usually 2, sometimes 1 . var. major. 



2. Sporocarps hirsute with erect hairs. Pedicels shorter 



than the sporocarps : — 

 Sporocarp distinctly ribbed ..... brachypus. 



Sporocarps not ribbed ...... gracilenta. 



II. Sporocarps always solitary. L. with interstitial strips of 

 sclerenchyma cells. Pedicels 2i-6 times as long as 

 sporocarp ........ coromandeliana. 



1. M. minuta, L. Syn. M. erosa, Willd. (including also M. quadri- 

 foliata of Bengal Plants). 



A slender very variable herb with a widely creeping much branched 

 slender rhizome, the growing tip hairy. Leaves very variable in 

 size, erose or entire, leaflets with many obliquely anastomosing nerves 

 meeting in the marginal nerve and without bands of sclerenchymatous 

 cells between, outer surface in vernation hirsute. Sporocarps -1" 

 long or more usually •12-18" long, ellipsoid, on pedicels as long to 

 twice as long as themselves, somewhat compressed and often with a 

 marginal ridge, strigosely hairy but glabrescent, nerves (not visible 

 externally) running without anastomosis to the opposite suture. Sori 



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