Common Name: Inkberry

General Information

Ilex glabra is an evergreen shrub that can grow around 0.5 - 4 metres tall and 2 - 3 metres wide. It spreads at the base by means of rhizomes and can form extensive, dense thickets[]..
The plant is harvested from the wild for local use as a food and source of materials. It is a popular ornamental, suitable for hedging and valued especially for its attractive evergreen foliage and autumn/winter display of white or black berries[, ]. There are several named cultivars[].
Iris glabra is a widespread and abundant North American shrub growing in a range of habitat types. There are no major threats affecting, or likely to affect this species, which has a stable population. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2018)[].

Known Hazards

Although no specific reports of toxicity have been seen for this species, Ilex species in general contain several potentially toxic compounds, particularly saponins, glycosides and triterpenoids. These compounds also often have a range of potential health benefits[, , ].
The berries are usually the part of the plant most likely to be toxic, though the degree of toxicity is usually low. Their bitter flavour usually prevents a person eating more than one or two, but even a small handful of the fruit eaten by a healthy adult is unlikely to cause more than feelings of nausea that can lead on to vomiting and diarrhoea[].
The compounds in the leaves are particularly interesting. The leaves of many Ilex species around the world are commonly used to make health-promoting teas that, when drunk on a regular basis, help to regulate bodily functions and can reduce the risk of heart disease, lower blood-cholesterol levels etc (See Ilex paraguariensis or Ilex kaushue for examples)[]. Even these teas, however, if taken in very concentrated doses, can act as a laxative or cause vomiting. Indeed, several species are used by traditional peoples to induce vomiting as a means of purifying the body (see Ilex guayusa or Ilex vomitoria for examples)

Botanical References

, ,

Range

Southern and eastern N. America - Texas to Florida, north to Maine and Nova Scotia

Habitat

Wet acid soils[]. Wetlands, bogs, seeps, swamps, lake, pond borders and creek bottoms along the coastal plains; also in pine flatwoods, pine barrens, prairies, terraces, and savannahs in more upland areas[].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	3.00 m
Growth Rate	Slow
Pollinators	Bees
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Ilex glabra is very cold-hardy, tolerating winter temperatures down to about -20°c, perhaps lower[, ]. Plants are very slow growing[] and seldom exceed 1metre in height in British gardens[].
Succeeds in most soils so long as they are not water-logged[]. Another report says that it needs an acid soil[]. This is one of the few evergreen shrubs that can thrive in continually moist to wet sites, and adapts to a wide range of light availability[].
Plants have stoloniferous roots[].
This species is closely related to Ilex coriacea[].
There are some named varieties, selected for their ornamental value[].
Resents root disturbance, especially as the plant grows older[, ]. It is best to place the plants into their permanent positions as soon as possible, perhaps giving some winter protection for their first year or two[].
Forest fires will usually kill the top growth of this plant, but it can regrow from the underground rhizomes[].
Plants are very tolerant of pruning and can be cut right back into old wood if required[].
A dioecious species - both male and female forms must be grown if fruit and seed are required. A report says that some plants are monoecious.

Edible Uses

The dried roasted leaves are a good substitute for yaupon tea. They contain caffeine[, , ]. The leaves contain mateine, a mildly stimulating relative of caffeine that tends not to produce side effects such as nervousness or sleeplessness[].

Medicinal

None known

Agroforestry Uses:

A good hedging plant, the var. 'Compacta' is used[].
The nectar of the flowers is an important source for honey production, producing a clear, light honey[, ],
The plant can be used within its native range for erosion control, watershed protection, and phosphate mine reclamation[].

Other Uses

None known

Propagation

Seed - best sown as soon as it is ripe in the autumn in a cold frame. It can take 18 months to germinate. Stored seed generally requires two winters and a summer before it will germinate and should be sown as soon as possible in a cold frame. Scarification, followed by a warm stratification and then a cold stratification may speed up the germination time[, ]. The seedlings are rather slow-growing. Pot them up into individual pots when they are large enough to handle and grow them on in light shade in a cold frame for their first year. It is possible to plant them out into a nursery bed in late spring of the following year, but they should not be left here for more than two years since they do not like being transplanted. Alternatively, grow them on in their pots for a second season and then plant them out into their permanent positions in late spring or early summer. Give them a good mulch and some protection for their first winter outdoors.
Cuttings of almost ripe wood with a heel, August in a shaded position in a cold frame. Leave for 12 months before potting up.
Layering in early autumn. Takes 2 years.