abstract abundant angular appearances backdrop background banded color colored coloring colors colour coloured colouring colours contrast contrasting cultivars curved dark dark-green decorative devil's-tongue display distinctive edges erect evergreen flat foliage hardy indoor-plant long mother-in-law's-tongue mottled ornamental outdoor-plant plant pointed rigid sansevieria snake-plant snake-tongue surface surfaces texture textures thick variegated all-weather-space Apocynaceae bark caudex caudiciform-plant conservatory displayed dome exotics fat-twisted-roots flower-dome fockea-edulis gardens Gardens-by-the-Bay glasshouse gnarled greenhouse grotesque ground-level horticultural horticulture Hottentot-bread indoors plants semi-deciduous shape shaped shapes Singapore South-Africa-native succulent tree trunk unusual utilitarian vegetation vine-branches bottle-shaped bottle-tree branched ceiba-chodatii deciduous floss-silk-tree inside palo-borracho South-American stored-water subtropical swollen-trunk tropical warty-tree angled angles botanical-gardens clouds columnless-glasshouse conservatories conservatory-complex construction controlled- temperature curves curving domes energy-efficient garden glass heating high-tech hothouse indoor-gardens light lighting optimized-conditions overcast palm-trees palms shrubbery shrubs steel structure sustainable-building-technologies transparent trees ventilation visibility warm-growing-environment windows atmospheric-humidity cloud-forest cooling regulated-climatic-conditions cool-moist environment flowers high mountain tall tallest unique water waterfalls