dried and are long lasting. While Hydrangea macrophylla is not considered a particularly difficult plant to grow, it may fail to flower. This may be due to cold winter damage to the flower buds, not getting enough sunlight, too much nitrogen fertilizer, or pruning at the wrong time of year. H. macrophylla forms flower buds in late summer. As a result, pruning in late summer, fall or winter could remove potential flowers. Chemistry Phyllodulcin, hydrangenol, and their 8-O-glucosides, and thunberginols A and F can be found in H. macrophylla. Thunberginol B, the dihydroisocoumarins thunberginol C, D and E, the dihydroisocoumarin glycosides thunberginol G 3'-O-glucoside and (−)-hydrangenol 4'-O-glucoside and four kaempferol and quercetin oligoglycosides can be found in Hydrangeae Dulcis Folium, the processed leaves of H. macrophylla var. thunbergii. The leaves also contain the stilbenoid hydrangeic acid. The various colors, such as red, mauve, purple, violet and blue, in H. macrophylla are developed from one simple anthocyanin, delphinidin 3-glucoside (myrtillin), which forms complexes with metal ions called metalloanthocyanins. Lunularic acid, lunularin, 3,4′-dihydroxystilbene and a glycoside of lunularic acid have been found in the roots of H. macrophylla. Hydrangine is another name for the coumarin umbelliferone, and may be responsible for the possible toxicity of the plant. Possible uses Amacha is a Japanese beverage made from fermented leaves of Hydrangea macrophylla var. thunbergii. Hydrangeae Dulcis Folium is a drug made from the fermented and dried leaves of H. macrophylla var. thunbergii with possible antiallergic and antimicrobial properties. It also has a hepatoprotective activity by suppression of D-galactosamine-induced liver injury in vitro and in vivo. Hydrangea macrophylla is included in the Tasmanian Fire Service's list of low flammability plants, indicating that it is suitable for growing within a building protection zone. Leaf extracts of Hydrangea macrophylla are being investigated as a possible source of new chemical compounds with antimalarial activity. Hydrangeic acid from the leaves is being investigated as a possible anti-diabetic drug as it significantly lowered blood glucose, triglyceride, and free fatty acid levels in laboratory animals. Cultivars The two main types of H. macrophylla cultivars are called "mophead" and "lacecap". Some popular hydrangea cultivars (those marked have gained the Royal Horticultural Society's Award of Garden Merit) include: 'All Summer Beauty'; cold-hardy, floriferous mophead 'Alpengluhen'; deep-red colored mophead 'Altona' ; compact plant with large rose-red florets 'Ami Pasquier' ; floriferous, wine pink to blue mophead 'Ayesha'; small, cupped, lilac-like flowers in clusters