Fruit of Castanea mollissima
Castanea mollissima, or the Chinese chestnut, is a medium-sized deciduous tree belonging to the Fagaceae. It has an open, rounded crown and typically reaches heights of up to 25m tall. The furrowed bark is grey to light-brown in colour. Its pinnately-veined leaves are simple and elliptic-oblong to oblong-lanceolate. They also have coarsely-serrated margins. The name mollissima means “soft” in Latin, and is in reference to the fuzzy leaf undersides and downy twigs (above, the leaves are shiny and dark green). In autumn, the foliage changes to various shades of yellow, gold and copper.
Chinese chestnut trees produce showy cream-coloured catkins in early summer. The blossoms are either staminate or pistillate, with the male flowers being borne in the showy catkins and the female flowers in aments at the bases of the catkins. The catkins are typically 10 to 20cm in length, while the aments are much shorter, at 1.3 to 1.9cm long. Castanea mollissima plants are generally self-sterile and insect-pollinated.
The formidably spiny cupules can be found underfoot from late summer to autumn, when they litter the ground like tiny green porcupines. These dehiscent fruit cases hold two to three glossy edible nuts, with each nut being 2.5 to 3cm in diameter and flattened on one or two sides. Chestnuts are said to taste astringent when raw, but, after roasting, are sweet with a floury texture.
Castanea mollissima is native to China, Taiwan, and Korea. The species can be found growing in forests and on some mountain slopes up to 2800m above sea level. In Asia, Castanea mollissima is cultivated for its edible nuts; cultivars developed for nut production include ‘Abundance’, ‘Meiling’, ‘Nanking’, and ‘Kuling’. Each tree can yield 25-60 kilograms of chestnuts in a harvest season. North American chestnut growers have begun cultivating hybrids of Castanea mollissima as an alternative to the American chestnut (Castanea dentata), as Chinese chestnut trees are much more resistant to chestnut blight (Cryphonectria parasitica). Castanea mollissima is also resistant to honey fungus (Armillaria spp.).
I also updated the Castanea sativa entry, if you are looking for additional details.
I’ve learned a few things from this posting. The fuzzy inside of the cupules was a revelation (and the term was new to me). I had no idea the genus would be pronounced, according to the efl.edu link: “kass-TAY-nee-uh”. I and have sort of learned the word “ament”, for which there is no hyperlink, understandably, since I can’t find any definition other than “catkin”, but here the term is used for the part of the inflorescence above the catkin. So when male and female flowers are on the same structure, the cats are Toms. Have I got this?
Also, from what I’m reading, I should be able to distinguish these from C. sativa by the presence of all those hairs. I’m very happy to read that, hope that works.
I’m enjoying your write-ups, Madeline.
That is one scary image. Fun to learn about this beautiful tree with the spiny fruit. Save this image for Halloween or an Alien movie marathon. Mahalo, Brynn
Here in Korea, I have never found any chestnuts to be astringent when raw; in fact, we eat peeled raw chestnuts when celebrating Chuseok. While they are not as sweet as the cooked ones, they clearly lack any astringency.
Of course, there is the possibility that the chestnuts commercially produced here are from non-astringent cultivars, but I doubt that since I have never found any wild trees producing astringent seeds as well, nor have I heard of such cases.
Thanks Lee, always welcome to have a local correction on assertions!
My neighbor has about 20 huge chestnuts along driveway. When the catkins are blooming, the smell is overwhelming and it is not a nice smell!
He had some kind of damage to the fruit itself and learned that the dropped spiny shells/seeds need to be scrupulously cleaned up in the fall. Once he started doing this, no more problems.
He has people who ask permission to come harvest the drops in fall. I think they are Italian. In Italy chestnuts are ground into flour and used in baking and probably other cooking.
correct me if I am not remembering correctly, but wasn’t Chinese chestnut the vector that brought the blight to North America?