In the spring of 2015, on a visit to a garden in California, I saw a plant (pictured above) which was unfamiliar to me and took a photo. Two years later, as I was idly flicking through a book of edible plants, its name jumped out at me, and I decided to do a little research.
In Sonoma County, California, tucked into a little valley on a hillside surrounded by vineyards, there is a very interesting garden. It is built into the shell of what was once a rock quarry, and from there the garden takes its name – Quarryhill.
Quarryhill is a botanical garden, which means that the plants are grown just as they are found in the wild, rather than being bred to have larger flowers or fruits like the big roses many of us have in our gardens. It’s akin to how one would find exotic wild animals like zebras in a zoo, but not domestic animals like dogs or cats. Botanical gardens are basically plant zoos.
Quarryhill specializes in asian plants, and incredibly, the plants there are grown almost exclusively from wild-collected seed. The lucky gardeners at Quarryhill get to go on seed collecting trips to the wilds of China, Korea, and Japan. This is very much in the spirit of the Victorian plant collectors, who would have romantic, swashbuckling adventures to distant lands, where, battling disease, language barriers, and unfamiliar surroundings, they would heroically persevere to bring back hundreds of newly introduced plants for the gardens of Europe.
The bone apple, also known by its Latin name, Osteomeles schwerinae, is a plant in the rose family (Rosaceae). A native of western China, it was first introduced to Europe in 1888, when Père Jean Marie Delavay, a French missionary then stationed in China’s Yunnan province, sent seeds to the Jardin des Plantes in Paris. Gardeners in Paris raised plants from the seeds, and from there the species was further distributed. It was introduced to the Royal Botanic Gardens, Kew in England just four years later.
The name Osteomeles (which means ‘bone apple’) is derived from Greek. ‘Osteo’ means ‘bone’ (like ‘osteoporosis’), while ‘meles’ means ‘apple’ (like the Botanical Latin name for apple, which is Malus). The name ‘bone apple’ is a reference to the hardness of the fruits, which are apparently edible despite their hardness.
In California, bone apples flower in April or early May, but in the UK, they don’t flower until June. The American Horticultural Society (AHS) finds bone apples suitable for United States Department of Agriculture (USDA) zones 7-11. The Royal Horticultural Society (RHS) finds bone apples to be frost hardy to -5ºC (23ºF).
When planting, it may be useful to note that bone apples favor a sunny position where they will not be subjected to cold winds. They like fertile, free-draining soil and prefer to be kept moist in summer and somewhat dry in winter.
The flowers, which have a sweet, honeyed fragrance, are typical of the rose family. Their five petals are evenly spaced, so they are symmetrical no matter which way they are turned. This is known as ‘radial symmetry’, and if you’re feeling fancy, there’s a special word for radial symmetry – ‘actinomorphy’. This word can be applied to daisies, starfish, and a whole host of other things in nature.
The petals are white and silky in a way that catches the light at dusk or dawn, turning them almost gold. That they are so much paler than their stems makes them appear almost as if they are floating just above the branches, like tiny star-shaped clouds.
Those fluffy, pollen-covered bits in the center (reproductive parts called ‘stamens’) are arranged in a spiral. That little spiral is just about visible if one looks closely.
While the flowers may be typical of their family, the leaves are actually somewhat unusual – at first glance, they more closely resemble those of plants in the the pea family, like vetch (Vicia).
An interesting chemical compound found in the leaves and twigs of O. schwerinae has been the subject of medical research. The lyrically named compound, OSSC1E-K19, has shown promise as a treatment for diabetes-induced vision impairment in trials on rats.
There seems to be some confusion around the classification of O. schwerinae. Some websites regard it to be the same as another species with white fruits, O. anthyllidifolia. However, all of the books referenced here (listed below) regard the two species as being distinct.
Sorry to throw around all this Latin, but unfortunately, both species are known by the same common name – ‘bone apple’.
The fruits are red when young, but like blackberries, they become a deep blue-black when they are ripe. Unlike blackberries, however, they remain hard when ripe, but are said to taste sweet. Since they are hard, one would think that they would be better after cooking, as for jam. References to the fruit of O. anthyllidifolia being used to make jam do appear on some websites, but similar information for O. schwerinae has proved elusive. Presumably, if the fruit can be eaten raw, then it can also be used to make jam.
Bone apples are an appealingly unusual culinary treat. I hope that one day I may be fortunate enough to try them! If anyone reading this has tried them, please let me know what they were like!
Study on the effects of OSSC1E-K19 on rats:
Quarryhill Botanical Garden Website:
General Information (books):
- Brickell, C. (2008). A to Z Encyclopedia of Garden Plants. 3rd ed. London: Dorling Kindersley in association with the Royal Horticultural Society. (Page 752). ISBN 9781405332965
- Hogan, S. (2004). Flora. 2nd ed. Portland, OR: Timber Press. (Page 962) ISBN 0881925381
- Mabberley, D. (2009). Mabberley’s Plant-Book. 3rd ed. Cambridge, UK: Cambridge University Press. (Page 614). ISBN 9780521820714
- Sturtevant, E. (1972). Sturtevant’s Edible Plants of the World. 1st ed. New York: Dover Publications. (Page 400). ISBN 0486204596
- Chittenden, F. and Synge, P. (1977). Dictionary of Gardening. 2nd ed. Oxford, England: Clarendon Press. (Page 1454). ISBN 0198691068
- Brickell, C. and Zuk, J. (2004). The American Horticultural Society A-Z Encyclopedia of Garden Plants. 2nd ed. New York, N.Y.: DK Pub. (Page 733). ISBN 9780756606169
General Information (web references):
- Gledhill, D. (2008). The Names of Plants. 4th ed. Cambridge University Press. (Page 285). ISBN 9780521685535