HARDY TREES AND SHRUBS. 149 



Berheris — Petals with two glands on the inside of each; stamens^ toothless; 



leaves^ undivided. 



Mahonia — Petals without glands; stamens, furnished with a tooth on each 



side; leaves, pinnate. 



Gentjs I. 



Berberis, (Berberry,) Hexandria Monogynia. — The species are all readily 

 propagated by seeds, suckers, and cuttings. Suckers are produced in abun- 

 dance. If some of the strongest of these were removed, they might be formed 

 into very handsome small trees. In all the species the flowers are yellow. 



Genus II. 



Mahonia, {Malionia,) Hexandria Monogynia. — The species are elegant ever- 

 green shrubs with yellow flowers, propagated by suckers, seeds, and by cuttings. 

 By some botanists the Mahonia is included in the genus Berheris. 



OEDER VII.— CEUCIACE^. 



The only shrub included in this order is the Vella Pseudo-Cytisus, (False 

 Cytisus, or Shrubby Cress Rocket. 



Genus I. 



Vella, (Vella,) Tetradynamia Siliculosa. — It is easily propagated by cuttings 

 of the young wood, in sand under a glass. 



ORDER VIII.— CISTACE.E. 



The hardy species are included in two genera, which are distinguished as 

 follows — 



Cist us — Capsule, ten, five-celled. 



Helianthemum — Capsule, one-celled, three-valved. 



Genus I. 



Cistus, {Bock Base, or Cistus,) Polyandria Monogynia. — The Rock Rose is 



propagated by seeds, which in fine seasons they produce in abundance; and by 



cuttings. 



Genus II. 



Helianthemum, (Sun Bose,) Polyandria Monogynia. — The Sun Roses are 

 natives of Europe, and of the easiest culture, propagated by cuttings; they 

 are beautifully adapted for rock or root work. 



ORDER IX.— MALVACE^. 



The only genus containing hardy species is Hibiscus, or Althcea Frutex. 



Genus I. 

 Hibiscus, (Hibiscus,) Monadelphia Polyandria. — The single-flowered varieties 

 are propagated by seeds, which come true to their respective colours, and the 

 double-flowered varieties by layers, grafting, and by cuttings in sand in autumn, 

 covered with a hand-glass. 



ORDER X.— TILIACE^. 

 The only genus which is perfectly hardy, is Tilia, native of Europe and 

 North America. 



