Boston ivy, Parthenocissus tricuspidata, Close-up detail of red autumn leaves.

Boston ivy, Parthenocissus tricuspidata, Close-up detail of green leaves turning red and yellow in autumn.

Boston ivy, Parthenocissus tricuspidata, growing across a bricked up window on a New York apartment block.

Boston ivy, Parthenocissus tricuspidata growing across a dilapidated window and air conditioning unit on a New York apartment block.

Boston ivy, Parthenocissus tricuspidata.

Boston Ivy, Parthenocissus tricuspidata.

Boston Ivy, Parthenocissus tricuspidata.

Bulgarian honey garlic, Nectaroscordum siculum bulgaricum, Side view of 2 flowerheads that have folded back in ready to turn to seeds, with Bronze fennel, Foeniculum vulgare 'Purpureum' and Honesty,...

Viola, Viola cornata Deltini series 'Honey bee', A frosted bronze, brown, orange and yellow coloured viola.

Bulgarian honey garlic, Nectaroscordum siculum bulgaricum

Silican honey garlic, Nectaroscordum siculum bulgaricum, in bud showing its papery sheath from which it has emerged.

Silican honey garlic, Nectaroscordum siculum bulgaricum, in bud showing its papery sheath from which it has emerged.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up of 2 single leaves showing serrated edges, cut out against white.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up of sprig showing serrated leaves cut out against white.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up showing serrated leaves.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up showing serrated leaves.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up showing serrated leaves.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up showing serrated leaves.

Sweet leaf, Stevia rebaudiana, a natural sweetener. Close up showing serrated leaves.