I’m not at all green fingered, but I could stare for hours at Berthe Morisot’s portrait of her sister Edma watering a shrub. She’s on the terrace of the Morisot family home on the fringes of Paris with her back to us. In one hand she clutches a jug, tilted towards a curvy green pot. In the other she hitches up the trailing ends of her house dress. Her feet resemble a ballerina’s, heels together, toes turned out. Her head is bent, engaged with her task. It’s a modest moment, fleeting and tender.