494 



ON SEEDLINGS 



No. 2. Pinnately trifoliolate ; terminal leaflet obovate, cuneate, 

 coarsely serrate ; lateral leaflets unequally or obliquely ovate. 



Acsena ovalifolia, Euiz et Pav. (fig. 318). 



Pistil apocarpous, superior, of one carpel which is one-celled, 

 one-ovuled ; ovule pendulous from near the apex of the ventral 

 suture, anatropous ; radical superior. 



Fruit an achene, oblong-fusiform, enclosed in the receptacle 

 which grows up around it, one-seeded, in- 

 dehiscent, glabrous, dark-coloured ; recep- 

 tacle obovoid or obconical, much narrowed 

 to the base, and again contracted at the 

 orifice enclosing the fruit, tipped with the 

 small persistent calyx-teeth, subtetragonal 

 and produced at its upper end into two 

 to four unequal spine - like appendages 

 tipped with small reversed barbs, glabrous, 

 loosely reticulate, dark brown. 



Seed conforming to the ulterior of the 

 achene, oblong, suddenly tapered to a 

 conical point just above its greatest 

 diameter, which is considerably above its 

 middle, pale straw-coloured, glabrous ; 

 testa thin, membranous ; micropyle and 

 hilum contiguous, inconspicuous, basal, 

 superior ; raphe forming a slender, slightly 

 darker line passing along one side ; 

 chalaza apical and inferior, forming a 

 brown spot on the lower end of the seed. 

 Endosperm absent. 

 Embryo straight, filling the whole of 

 FIG sia.-Acvna ovalifoUa, the interior of the seed, colourless ; coty- 



x 10. Longitudinal section ; 



of the fruit: Ac, achene; ledons oblong, obtuse, entire, minutely 



Saut^P-el^/au-' auricled at the base > ^no-convex with 



ride; B, barbs or bristle- their edges generally to the two larger 



spines of the pericarp, but sometimes 



obliquely to them ; radicle turbinate or shortly conical, obtusely 

 pointed, lying in the conical tip of the seed, about a third or a 

 quarter as long as the cotyledons. 



Acaena myriophylla, Lindley (fig. 319). 

 Primary root simple, tapering. 



Hypocotyl mostly subterranean, terete, glabrous, colourless below 

 and green where exposed, 7-9 mm. long. 



