170 



xATi~n.iL nrsTOiiY of plants. 



and five alternate petals, imbricated in the bud, sessile, but tapering 

 at the base, which in certain species is thickened and glandular- 

 The stamens, indefinite in number, are all nearly free, or obscurely 

 united at the base into five oppositipetalous bundles. The filaments 

 are inserted close against the corolla ; their summit is divided into 

 two very short divergent branches, each of which supports a distinct 

 anther-cell, extrorse and dehiscing longitudinally. 1 The free and 

 superior gynceceum, inserted immediately above the stamens, is com- 

 posed of an ovary with five alternipetalous cells, surmounted by a 

 style slightly dilated, quinquedentate, stigmatiferous at the apex. 

 In each cell, more or less complete, 2 there are two ascending ana- 



Tilia sylvestris. 



Fig. 179. 

 Flower (f). 



Fig. 180. 

 Diagram. 



Fig. 181. 

 Long. sect, of flower. 



tropous ovules inserted towards the internal angle, ascendent and ana- 

 tropous, the micropyle being directed downwards and outwards. 3 The 

 fruit is dry, 4 inclehiscent, containing one or a very small number of 

 seeds, which enclose under their coats 5 a fleshy albumen enveloping 

 an embryo with large, superior, foliaceous, lobed 6 cotyledons, whose 

 summit and edges are more or less irregularly incurved and involute. 



1 The pollen is ellipsoidal, flattened, slightly 

 triangular, with a large halo and a small pore 

 on each face ; it differs thus from that of the 

 other Tillacece where it is ovoid with three folds, 

 and in water ovoid or spherical with three bands 

 each bearing a papilla. Its external envelope is 

 finely cellulose in O-rewia, and punctuate in 

 Elceocarpus, Sloanea, Imhea, Triumfetta, Cor- 

 chorus and Sparmannia. (H. Mohi., in Ann. 

 Sc. Nat., se*r. 2, iii. 333.) 



2 The placentas, which are always parietal 

 when young, join sooner or later, more or less 

 completely, according to the axis of the ovary ; 



in this way the upper part is quite different 

 from the lower which has another origin, for it 

 arises directly from the floral axis. (See 

 Payee, Organog., 24.) 



3 They have two coats. 



4 Or rather its mesocarp is represented at 

 first by a slight fleshy layer, finally becoming 

 dry. 



5 They are three-fold. The testa is thick 

 and crustaceous ; its internal edge often bears 

 a large irregular impression (fig. 1S3). 



6 Digitinerved at the base. 







