130 



ON SEEDLINGS 



segmented and forming a more or less conspicuous transverse ridge 

 between each seed, each of the latter being contained in a separate 

 Iccellus by a transverse development of cellular tissue. During ger- 

 mination the pod or its segments separate slightly along both 

 sutures to allow the seedling to get out. 



Seed lenticular, somewhat flattened laterally but con vex, rounded 

 on all the edges except the ventral, which is straight, deep brown or 

 almost black, very minutely and inconspicuously glandular or reticu- 

 late. 



Germination. When the seeds swell, the pod bursts along both 

 sutures and the radicle protrudes, fixes itself deeply in the soil, 

 and together with the lengthening and straightening hypocotyl 

 assists the cotyledons in making their exit from the seed and 

 pod. 



The cotyledons are linear, acute, tapering upwards, and very 

 slender, semiterete at the base, and more or less completely terete 

 upwards, 14-20 mm. long. By their growth in length during 

 germination their exit from the seed 

 and pod is materially assisted. 



Seedling (fig. 153). 



Primary root slender, tapering, with 

 a few lateral rootlets, annual. 



Hypocotyl terete, tapering indistin- 

 guishably into the primary root, gla- 

 brous, pale green, 3-5 mm. above the soil. 



Cotyledons subulate,much attenuated, 

 slender, tapering upwards from a dilated 

 connate base, sessile, grooved from the 

 base for some distance upwards, pale 

 glaucous-green, fading to a yellowish 

 green when old, glabrous, entire, 2-8-3' 2 

 cm. long, about 1 mm. wide near the base. 



Stem annual, developing when about 

 to flower; primary internodes unde- 

 veloped. 



Leaves simple, radical and cauline, 

 alternate, exstipulate, petiolate, pin- 

 nately multisect, with the venation 

 ramifying accordingly, and sending a 



nerve into every branch or segment, glabrous, glaucous, with 

 slender segments, covered with minute glands; petioles semi- 

 terete, flattened or convex above but channelled towards the 



FIG. 153. Hypecoum pro- 

 cumbens. Nat. size. 



