THE NURSERY-LIST 337 



Hydrangea, Hortensia. Saxifragacece. 



Seeds may be employed when they are produced; but usually 

 the hardy species are propagated by green cuttings in summer, 

 under glass (see Fig. 112). The tender ones (H. opuloides, the var. 

 Otaksa, etc.) are increased by cuttings taken at any time from 

 vigorous young wood, usually in late winter. Layers are occa- 

 sionally employed, and suckers can be separated from some species. 

 Sometimes the hardy species are forced for purposes of propaga- 

 tion by cuttage. H. quercifolia is propagated by little suckers or 

 " root pips." H. paniculata var. grandiflora can be propagated 

 easily from the young wood, taken in June and planted under 

 glass. 



Hydrastis (Goldenseal) . Ranunculacece. 



Seeds sown in autumn or spring in a well-protected shady place 

 should grow readily. Old plants or colonies may be divided. 



Hydriastele. Palmacece. 



Propagated by seeds. See Palms, page 377. 



Hydrocleis (Water-Poppy). Butomaceae. 

 Propagated by dividing the rooting stems. 



Hydrocotyle (Water Pennywort). UmbellifercB. 



Increased by seeds, cuttings or layers. Usually spreads by the 

 rooting stems. 



Hylocereus (separated from the old genus Cereus). Cactacece. 

 For propagation, see Cacti, page 261. 



Hymenocallis. Amaryllidacece. 



Increased by offsets from the bulbs. Treated the same as 

 amaryllis and pancratium, which see. 



Hymenophyllum (Filmy Fern). Hymenophyllacece. 



Propagated by spores and by dividing the roots. See Ferns. 



Hypericum (St. John's-Wort). Hypericacece. 



Most of the species grow readily from seeds. Some of them pro- 

 duce runners that may be used as cuttings or layers. The shrubby 

 kinds are handled by cuttings of green wood under glass in summer. 

 Division may be practiced in some cases, and suckers may be 

 removed when they are produced. 

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