CARYOPHYLLE^E 



217 



Tunica pachygona, Fisch. et Mey. 



Capsule oblong-ellipsoid, glabrous, enclosed in the shortly five- 

 toothed, fifteen-ribbed, persistent calyx, which is nearly or quite as 

 long, one-celled, with a central placenta, and many seeds, dehiscing 

 at the apex by four valves. 



Seed oblong-orbicular, thin and much flattened dorsally, entire 

 or slightly angled at the margins, winged all round except at the 

 tip of the radicle where a narrow shallow sinus is formed, glabrous, 

 black. Except for an elevation conforming in outline to that of 

 the embryo the seeds are nearly flat and attached to the placenta a 

 little above the middle and much overlapping one another ; hilum 

 forming a little round spot above the middle of the seed on the 

 ventral aspect ; micropyle at the lower end of the seed, lying in the 

 sinus ; raphe and chalaza inconspicuous. 



Endosperm forming a thin layer throughout the seed, except in 

 the wing, but much thinner around the embryo, white, fleshy, or 

 subfarinose. 



Embryo straight, central, much narrower than 

 the endosperm and a little shorter, colourless ; 

 cotyledons oblong-ovate, obtuse, entire, plano-con- 

 vex or nearly flat, lying in the broad plane of the 

 seed with their backs to the axis ; radicle terete, 

 obtuse, about ha]f as long as the embryo, embedded 

 in a thin layer of endosperm close to the micropyle. 



Tunica prolifera, Scop. (fig. 198). 



Primary root slender, tapering, flexuose, with 

 a few short lateral rootlets. 



Hypocotyl suberect, herbaceous, about 2 cm. 

 long, -5-1 mm. thick, round, slightly pubescent 

 under the seed-leaves. 



Cotyledons nearly equal, stalked, including 

 petiole about 1 cm. long, 7 mm. broad, sub- 

 orbicular or somewhat spathulate, rounded, entire, 

 with very obscure nervation, glabrous, not very 

 thick nor persistent, dull green above, paler 

 below. 



Stem very short, elongated when about to flower. 



Leaves simple, entire, radical and cauline, opposite, exstipulate, 

 petiolate in the early stages or very much narrowed at the base, 

 ultimately narrow, sessile, with a distinct midrib and a few scattered 

 lateral nerves, glabrous, deep green above, paler beneath. 



1st and 2nd pairs spathulate, much narrowed to a petiole.like base. 



FIG. 198. 



Tunica prolifera. 

 Nat. size. 



