black brittle closeup Dandelion grow grows head heads macro milky nature parachute plant plants sap seed seeds spread taproot white wind barb barbs botanic garden cactus desert plant echinocactus gardening glasgow Golden Barrel Cactus growing grusonii old stings thorn colourful contrast difference environment establish ghastly growth inhospitable leaf leaves pavement penetrate rock rocks spring way bark coast coconut date palm foliage island mata night palm palm tree palma tree tropical vegetation cover cultivate cultivation farm farming field frame fruit greenhouse hoops plastic poly polytunnel protect raspberries semicircle shelter strawberries tunnel