Celtis reticulata

Celtis Reticulata

Hackberries
(closeup of split seed and fruit)

Celtis reticulata is a small tree which I find mostly at the mouths of canyons in my area. It is commonly known as Net-leaf Hackberry. This species is mainly noticeable because of the leaves. The leaves have a surface texture like sandpaper, and are fairly tough, so that they can stay on the tree all winter. The berries also persist on the tree all winter, which makes it even more noticeable when all the other deciduous trees have lost their leaves. The other distinctive feature of the leaf is the base of the leaf, which joins the leaf stem (petiole) at an angle. Finally, the bark has prominent ridges or bumps, at least on the larger trunks, but these are much more noticeable feature of the larger Celtis occidentalis (common Hackberry) which is found in the eastern United States. Being a small tree makes it easier to gather the berries from my local species.

The fresh, ripe berries are orange, round, less than a centimeter wide, and grow from the axils of the leaves. They have a large seed with a thin layer of yellow fruit. The seed has a hard brown shell, and a white kernel. At this stage they have a fresh, sweet taste which is mildly reminiscent of apricot. 

The berries persist on the tree in the winter and even through the next year, so they can be a source of food in winter and in the early spring. They remain edible all winter because, as Samuel Thayer notes, they are high in sugar and low in water, and also, as noted below, the fruit flesh is resistant to bacteria and fungus infestations. The older berries have a red skin, and persist on twigs without leaves, or with leaves which are old and dry. The fruit dries to a leathery but soft texture, not hard and dry. The old berries are still edible but the taste intensifies. Others who tried it said it tasted sort of like an apricot fruit leather. I thought it tasted like honey-flavored fruit leather, just not nearly as sweet as honey.

The seed is also edible, but the hard shell can be difficult to bite into, especially in old berries. Using a mortar and pestle, two rocks, the flat of a knife, or other grinding appliance is helpful for eating the full berry. This is worth it if you are doing more than just tasting, because the kernel is high in protein and fat, even though it has little flavor. Smashing the fruit and grinding it into a paste gives you a palatable, if rather crunchy, meal.

But a better option for getting the nutrition from this hard seed is to crush it and mix it with water to make "hackberry milk", which is similar to other nut-milks, such as almond milk or cashew milk, but has its own mildly sweet flavor. For convenience, I use a blender, and blend 1 part hackberries with 4 parts water, then strain. The result is a thickish liquid (like milk) which tastes like drinking liquid hackberries. One excellent use for hackberry milk is as a base liquid for Thai Curry (instead of coconut milk). Just mix one tablespoon of red curry paste in 2-4 cups of hackberry milk, and add to your cooked meat and vegetables.

Tree in winter, with
dried leaves and fruits

Botanists placed the Celtis genus in the Elm family (Ulmaceae) based on morphology (physical characteristics). More recently, geneticists have placed it in the Cannabis family (Cannabaceae). Unlike cannabis, there is no evidence of any harmful or psychoactive chemicals, although there is evidence of antibacterial and antifungal activity, as well as antioxidants. This helps the berries stay good on the tree all winter, and also means they can be easily stored for months without refrigeration. Native Americans are reported to have used this plant to treat indigestion.