352 ON SEEDLINGS 



very broadly oval. The cotyledons of Thunbergia alata (fig. 

 576) are rotund-oblong, entire, cuneate at the base and tri- 

 nerved with long petioles, as the hypocotyl scarcely appears 

 above ground. The first two pairs of leaves are triangular- 

 hastate, slightly and irregularly dentate, five-nerved and 

 suddenly decurrent upon the long petioles, forming narrow 

 wings to them. Asystasia coromandeliana (fig. 582) differs in 

 having unsymmetrically orbicular slightly emarginate cotyle- 

 dons, suddenly tapering into their petioles. The leaves of 

 first pair are ovate with an incurved anastomosing venation 

 similar to that of Peristrophe speciosa. A very remarkable 

 type is met with in Thunbergia reticulata ; the cotyledons 

 are unequal, orbicular, trinerved, cordate at the base and 

 minutely denticulate at the margin, particularly the larger 

 one which has a peculiar elevation in the centre. Another 

 case of unsymmetrical cotyledons is met with in Dicli- 

 ptera resupinata where they are oblong, emarginate, tri- 

 nerved and rather deeply sinuated on one side or almost 

 falcate. Those of Justicia bracteata are obovate-oblong, 

 emarginate, trinerved, and somewhat reticulated. Another 

 curious development in the same direction is met with in 

 Schwabea ciliaris, which has oblong, emarginate, one-nerved, 

 fleshy, shortly petiolate cotyledons. The hypocotyl is greatly 

 elongated and finely hairy, as is the first internode of the 

 stem. The first three pairs of leaves are lanceolate and 

 penninerved with ascending nerves. 



Thunbergia alata, Boj. (fig. 576). 



Hypocotyl short, terete, pale green, densely pubescent. 



Cotyledons large, foliaceous, petiolate, deep green above, paler 

 beneath, densely pubescent on both surfaces ; lamina rotund-oblong, 

 trinerved, subcuneate at the base, 2'6 cm. long, 2*5 cm. wide ; petiole 

 channelled above, pubescent, 2-7 cm. long. 



Stem herbaceous, erect, ultimately twining, terete, thickened at the 

 nodes, densely pubescent, green, purple at the nodes ; 1st internode 

 1-7 cm. long ; 2nd 6-5 cm. ; 3rd 7'2 cm. ; 4th 17 cm. ; 5th 

 15 cm. 



Leaves simple, cauline, opposite, exstipulate, petiolate, softly and 

 densely pubescent on both sides, ultimately rough and scabrous above, 

 and deep green, paler beneath ; petioles convex on both surfaces, 



