all-weather-space bark branched branches caudex conservatory deciduous display displayed distinctive dome dormant dorstenia-gigas exotics flower-dome gardens Gardens-by-the-Bay glasshouse gnarled greenhouse grotesque horticultural horticulture indoors moraceae ornamental pachycaul-shrub plants shape shaped shapes Singapore Socotran-fig-tree succulent surface surfaces texture textures tree trunk unusual utilitarian vegetation Apocynaceae caudiciform-plant fat-twisted-roots fockea-edulis ground-level Hottentot-bread semi-deciduous South-Africa-native vine-branches