HARDY PERENNIAL PLANTS 205 



ONOSMA. 0. stellulatum var. tauricum is a dwarf, evergreen 

 plant, forming dense tufts of narrow, hairy leaves. The flowers, 

 which are bright yeUow, tubular, and ij^ inches long, are arranged 

 in branching cymes. It succeeds weU on high groxmd or sunny 

 rockery, with hght, open, deep soO. 



Propagation. The plant is best propagated by seeds, and by 

 cuttings of the ripened growths taken during the end of September. 

 They must be rooted cool. 



OPHIOPOGON. The most useful species of these dwarf ever- 

 green plants is O. gracilis; it is used for planting in dense shade 

 where few other plants thrive. The leaves are narrow; Howers 

 small, white, followed by beautiful blue berries, which con- 

 tinue on the plant all Winter. A. Jaburan is a taller species; the 

 variegated form is a handsome plant. O. japonicus has also a varie- 

 gated form. It is used much as a dark green lawn-cover standing 

 well in a drought. It needs no clipping and does well under the 

 shade of trees. 



Propagation. Increased by division in Spring. 



OROBUS (Bitter Vetch). The species O. vernus, often classed 

 under Lathyrus, comes in bloom during April and lasts only for a 

 short time. The flowers on opening are purple and blue, the purple 

 changing to blue as the blossoms mature. They differ from the 

 Lathyrus, in that they have no tendrils. There are several other de- 

 sirable species, such as O. pannonicus, O. flaccidus and O. aurantia. 

 The above are seldom listed in American catalogues. They are of 

 comparatively easy cultivation. 



Propagation. Seeds should be sown as soon as ripe. As the 

 plants make but little headway during the first season they should 

 be allowed to remain in the seed pan till the following Spring. 



PACHYSANDRA. There are only two species in this genus, 

 both of which are in cultivation. P. procumbens is a North American 

 plant. The flowers are very inconspicuous, produced in March and 

 April at the bases of the stems made the preceding year. In P. 

 terminalis they are situated on the ends of the shoots. Both species 

 are evergreen. P. terminalis is of a brighter green than P. pro- 

 cumbens. They are very useful for planting under trees; are deep- 

 rooting and stand drought well. They are good for rockeries. 



Propagation. Easily propagated by division. 



P.i^ONIA (Pseony, Peony, or Piony). This genus is divided 

 into two sections or sub-genera — shrubby (see p. 326) and herba- 



