Persian Silk Tree The Persian Silk Tree (Albizia Julibrissin 'Summer Chocolate') was declared the most promising newcomer to the market in 2006. It is a highly exclusive garden subject with its pinkish summer flowers and unusually coloured tripinnate sickle-shaped leaves. It is a distant relative of the more common acacia and mimosa. It is hardy and has a delightful fragrance which attracts butterflies. Height supplied 25-30 cm.