AN ENCYCLOPEDIA OF HORTICULTURE. 



163 



Hydrangea continued. 

 H. b. Otaksa (Otaksa).* fl. flesh-coloured, nearly all sterile, dis- 



posed in large, terminal, globose, leafless cymes. I. opposite, 



cuneate-obovate, deeply serrated, h. 2Jft. Japan, 1868. Hardy. 

 H. b. stellata prolifera (proliferous star-like), ft. at first 



yellowish-green, ultimately rose-colour, sterile ; cyme terminal, 



densely packed. Japan, 1868. 



H. h. variegata (variegated) is a variety with very ornamental 

 foliage, particularly when gr 



grown as young plants, in heat. 



Fio. 253. HYDRANGEA PANICULATA GRANDIFLORA, showing 

 Habit and detached Single Flower. 



H. panlculata grandiflora Oarge-flowered panicled).* fl. white, 

 disposed in a large, terminal, leafy panicle, 1ft. long, consisting of 

 openly-arranged, small, star-shaped flowers, intermixed through- 

 out with sterile ones, more than lin. across. Summer and 

 autumn. I. opposite, or in threes, ovate-oblong, acute, pu- 

 bescent. Japan, 1874. Hardy. See Fig. 253. 

 H. petiolaris (petiolar).* fl. white, in flat-topped cymes, Sin. 

 to lOin. in diameter ; fertile flowers greenish, very numerous ; 

 stamens fifteen to twenty. April and May. I. broadly ovate- 

 cordate, acuminate, finely serrate, dark green above, paler be- 

 neath ; stalk pubescent, and nerves bearded in axils. Trunk 

 slender, branching, rooting like Ivy against its support. Japan, 

 1876. Cool conservatory. (B. M. 6788.) Now and then met with 

 in gardens under the name of Schizophragma hydrangeoides, a 

 very different plant. 



H. quercifolla (Oak-leaved).* fl. white, sterile, or outer ones 



large ; corymbs rather panicled, flattish. Summer. I. large, 



ovate, sinuately lobed and toothed, pilose beneath, h. 4ft. to 6ft. 



Florida, 1803. Half-hardy or greenhouse. (B. M. 975.) 



H. scandens (climbing), fl. white ; petals cohering at their tips 



and falling together. Japan, 1879. Plant climbing, half-hardy. 

 H. Thunbergli (Thunberg's).* fl. blue or rose ; the sterile ones 

 on the circumference, and fertile ones in the centre, of the cyme ; 

 cymes terminal, 3in. to 4in. in diameter. I. opposite, petiolate, 

 ovate-oblong, acute, serrulate, h. 2ft. to 3ft. Japan, 1874. 

 Half-hardy. (G. C. 1870, 1699.) 

 HYDRANGE2E. A tribe of Saxifragece. 

 HYDRASTIS (probably from hydor, water, and 

 drao, to act; in allusion to the active properties of the 

 juice). OBD. Ranunculacew. A monotypic genus, the 

 species being a hardy herbaceous perennial. It is of 

 somewhat difficult culture, and must be grown in loam 

 and leaf mould, in a moist situation. Increased by divi- 

 sions of the root. 



H. canadensc (Canadian). Orange Boot. fl. greenish-white, 

 small, solitary ; petals none. May and June. I. rounded, heart- 

 shaped at the base, five to seven-lobed, doubly serrate, veiny ; 

 when full grown, in summer, 4in. to 9in. wide. Stem simple, 

 hairy. A. 1ft North America, 1759. (B. M. 3019, 3232.) 



HYDRIASTELE (from hydria, a water vessel or 

 fountain, and stele, a column ; in allusion to the tall 

 stems growing near springs). OBD. Palmea. A mono- 

 typic genus, the species being a tall stove palm. For 

 culture, see Kentia. 



H. Wendlandiana (Wendlaud's). fl., panicle of numerous 

 slender pendulous spikes of about 1ft., the common peduncle very 

 short, broad, and thick, marked with the scars of the spathes and 

 of two outer bracts ; spathe and male flowers unknown ; female 

 perianth under the fruit, the segments all very broad, the inner 

 twice as long as the outer ones. fr. ovoid or globular, when dry 

 longitudinally striate with prominent ribs, succulent when fresh, 

 with a thin endocarp. I. many feet long ; segments numerous, 

 unequal, the longest lift, long, the upper ones confluent at the 

 base, all or mostly jagged or toothed at the apex. Tropical 

 Australia. SYN. Kentia Wendlandiana. 



HYDROCHARIDE2B. A small order of aquatic 

 herbs, widely diffused over the globe. Flowers in 

 spathes, often incomplete ; perianth of six segments, the 

 three inner often petaloid. Leaves undivided, floating 

 or submerged, opposite or whorled. There are about 

 fourteen genera and forty species. Examples : Hydro- 

 charis, Ottelia, Stratiotes, Vallisneria. 



HYDROCHARIS (from hydor, water, and charis, 

 grace; a pretty water plant). OBD. Hydrocharidece. A 

 monotypic native aquatic genus, spread over Europe and 

 North Asia. The species thrives in any still water. It 

 may be readily increased by seeds ; or by runners, 

 which root at the joints. 



H. Morsus-ranae (Frogbit). fl. rather large ; outer segments 

 of perianth pale green, shorter and narrower than the inner 

 white ones ; peduncles of male plant rather short, bearing two 

 or three flowers ; pedicel of female enlarged at top into a short 

 perianth tube. Summer. I. stalked, orbicular, entire, cordate 

 at base, rather thick, about 2in. in diameter. Stems floating, with 

 floating tufts of leaves, peduncles, and fibrous roots. (Sy. En. B. 



HYDROLEA (from hydor, water, and elaia, oil; 

 alluding to the habitat and nature of the plants). SYNB. 

 Reichelia, Sagonea, Steris. OBD. Hydrophyllacece. A 

 genus comprising about fourteen species of herbs or 

 sub-shrubs, inhabiting North and South America, tropical 



FIG. 254. FLOWERING STEM OF HYDROLEA SPINOSA. 

 Africa, the West Indies, the Malayan Archipelago, and 

 tropical Australia. Flowers blue, axillary or terminal: 

 corolla broadly campanulate-rotate, five-fid ; lobes im- 

 bricated. Leaves alternate, entire. The species require 

 damp, boggy positions to thrive thoroughly. 



