HENDERSON'S HANDBOOK OP PLANTS. 



ASC 



pervades all their parts being eminently 

 emetic and purgative. 



The genera Sfapelia, Hoya, Asclepias, 

 Vincetoxicum, Ceropegia, Periploca, are 

 good examples of the order. The man- 

 ner in which the ovules of these plants 

 are fertilized by the pollen is among the 

 most curious phenomena known in plants. 

 Instead of the grains of pollen falling on 

 a viscid stigmatic surface, and then pro- 

 ducing tubes of impregnation, the tubes 

 are formed inside the pollen bags, whence 

 they ultimately find their way by a spon- 

 taneous emission, and reach the surface 

 of the stigma without being projected 

 upon it, conducted by some inherent 

 vital power. For a full account of this 

 extraordinary fact, see Lindley's In- 

 troduction to Botany, fourth edition. 



Asdepiadece. A synonym of Asclepiadacece. 



Asdepiads. The English name for Asdepi- 

 adacece. 



Asexual. This term was once applied to 

 Cryptogamice, but since the discoveries 

 which have been made during the last 

 thirty years, it is no more applicable to 

 them than to Phcenogamice. Sexual or- 

 gans have now been discovered in 

 every branch of Cryptogamios. Among 

 Fungi alone they are still obscure in 

 several divisions; but if such genera as 

 Leptomitus really belong to Fungi, of 

 which there is little doubt, there is even 

 among them the same type as among the 

 higher Cryptogamice. It is, moreover, 

 singular that the impregnation of Cryp- 

 togamice comes nearer the type of that in 

 animals than in Plwsnogamice. Their 

 spermatozoids resemble closely those of 

 animals, and, indeed, are often more 

 complicated. Among Fungi alone, and 

 Lichens, which nearly approach Fungi, 

 they are mere cells, without motion, anal- 



ASP 



ogous to pollen grains, though they do 

 not germinate like them, at least so 

 far as has been observed at present. 



Aspect. This term is used to denote the posi- 

 tion of garden or grounds. When choice 

 can be made, it should be towards the 

 south or southeast, and if it has a gentle 

 slope to the south or southeast, say one 

 foot in a hundred, so much the better ; 

 and if well sheltered by hills or woods 

 from the northwest, many plants can be 

 safely grown that would not be sufficient- 

 ly hardy without that shelter. Such an 

 aspect also permits operations to be be- 

 gun earlier in spring, and will longer re- 

 sist the fall frosts, than if such shelter 

 was not present. Such aspect is equally 

 important for all glass structures. 



Asperifolice. An old name for what are now 

 called Borageworts, or Boraginacece, de- 

 rived from the remarkable roughness of 

 the leaves of the greater part of the spe- 

 cies. 



Asphodelece. An order of herbaceous plants 

 now merged in Liliacece, from which they 

 were found to differ in no essential char- 

 acters; a group of monocotyledons, which 

 may be considered as a distinct natural 

 order, or referred to Liliaceee as a subor- 

 dinate tribe. 



Aspidiece. A section of polypodineous 

 Ferns, in which the sori are punctiform 

 or dot-like, and covered either by reni- 

 form or peltate indusia. See Indusia. 



Aspkniece. A section of polypodineous 

 Ferns, in which the simple linear or ob- 

 long sori are parallel with the veins, and 

 oblique to the midrib, produced on one 

 side of the veins, and covered by indu- 

 sia of the same form. The modern group, 

 Aspleniece, is nearly synonymous with 

 the genus Asplenium of the older and 

 some modern writers. 



