ACANTH AGILE 359 



Seed large, obliquely oblong or ovate, dorso-ventrally compressed, 

 but chiefly ventrally, smooth or variously wrinkled and ridged ; testa 

 coriaceous, deep brown ; tegmen thicker, paler ; hilum obliquely 

 basal ; micropyle on the opposite 

 side from the hilum and near the 

 middle of the seed ; seed 13 mm. 

 long, 7-10 mm. broad, 5 mm. 

 thick. 



Endosperm absent in the ma- 

 ture seed ; but previous to ma- 

 turity forming a layer or cup en- 

 closing the growing embryo, close 

 to the hilum and at the base of 

 the seed, fleshy. 



Embryo straight, transverse, FIG. 579,-Acanthus longifoliua, * s. 



large and ultimately Occupying Longitudinal section of seed: M, 



the whole interior of the seed ; ^\ &*$.*' ^ f 

 cotyledons oblate-orbicular, plano- 

 convex, rather deeply cordate at the base with the auricles closed 

 over the radicle, and having an oblique impression on one side 

 near the apex caused by the attachment of the retinaculum, equal 

 in length and breadth to the seed, closely applied face to face ; 

 radicle transverse to the seed, short, obtuse, included between the 

 cotyledons. 



Acanthus spinosus, L. 



Ovary surrounded at the base with an annular disk, two-celled ; 

 ovules attached a little above their bases to long retinacula of which 

 there are two in each cell pointing alternately right and left ; ovules 

 oblique, amphitropous or semianatropous, with the radicle in the 

 growing condition, at a point in a diagonal line with the insertion 

 on the retinaculum. 



Capsule obovoid, compressed or subcompressed, antero-posteriorly 

 tipped with the woody remains of the base of the style, or its whole 

 length, glabrous, deep green and shining. 



Seed elliptic, compressed, with a slender ridge along the dorsal 

 and ventral flattened aspects, on the latter of which it is grooved 

 towards the base by pressure against the retinaculum, glabrous, 

 brown ; hilum obliquely basal ; testa very thick and succulent when 

 growing. 



Endosperm in the growing seed farm, transparent, succulent and 

 watery, occupying the lower part of the seed, stretching across the 

 interior diagonally and abutting against the embryo, gradually 



