The taxonomic history of Prunus is long and complicated, in part due to the economic value of its fruit crops and also the ease with which some species hybridize. Here, Prunus is circumscribed in its broad sense based on the argument that when viewed on a worldwide scale, the morphologic discontinuities among the segregate genera diminish and they overlap with one another. Included here are species that have at times been placed in the genera Amygdalus, Armeniaca, Cerasus, Laurocerasus, Padus, and Persica.
At the species level, Prunus has been the object of the usual combining and splitting common among taxonomists with different philosophies and opinions. In particular, over-reliance on the indument of various vegetative and floral parts has led to the naming of numerous species and infraspecific taxa. Similarly, too much has been made of fruit colour and palatability in naming taxa of Prunus. It is very likely that, as molecular and genetic data are analyzed and, more importantly, correlated with morphological data, circumscriptions will be redrawn and the number of Prunus species will be reduced[].

Common Name: Holly-Leaf Cherry

General Information

Prunus ilicifolia is an evergreen shrub or a tree, it can grow from 1 - 15 metres tall. The plant sometimes produces suckers[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is used to stabilize soils on steep slopes and is often grown as an ornamental, especially in California, where it is valued for its holly-like, evergreen foliage[].

Known Hazards

The plant (especially the seed and young shoots) contains cyanogenic glycosides, especially amygdalin and prunasin. When injested, these compounds break down in the digestive tract to release cyanide. Used in small quantities in both traditional and conventional medicine, this exceedingly poisonous compound has been shown to stimulate respiration, improve digestion, and promote a sense of well-being[]. It is also claimed by some to be of benefit in the treatment of cancer - though this claim has been largely refuted.
In larger concentrations, however, cyanide can cause gasping, weakness, excitement, pupil dilation, spasms, convulsions, coma and respiratory failure leading to death[].
The fruits and flowers of most members of this genus generally have low or very low concentrations of this toxin, though the seeds and young shoots can contain much higher levels.
The levels of toxin can be detected by the level of bitterness:- for example sweet tasting almond seeds are a major food crop and are often eaten in quantity, whilst bitter tasting almond seeds are used as a flavouring (in marzipan for example) but are not usually eaten on their own.
In general, it can be considered safe to eat any fruit or seed from species in this genus that either have a sweet flavour or are slightly bitter. Great caution should be taken, however, if the flavour is moderately to very bitter[].

Botanical References

, ,

Range

South-western N. America - California, northwestern Mexico.

Habitat

Borders of streams and moist sandy soils, where it makes a small tree. It is also found on dry hillsides where it is only a shrub[]. Chaparral, woodlands, canyons, slopes, and ridges; at elevations up to 1,600 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	4.00 m
Growth Rate	Medium
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Prunus ilicifolia is not very hardy in much of the temperate zone, tolerating occasional, short-lived temperatures falling to around -3 to -5°c. Young plants are very susceptible to frost damage, though they become somewhat hardier as they age[].
Requires a well-drained moisture retentive soil[]. Succeeds in a hot dry position. Succeeds in full sun but prefers a position with some shade[]. Thrives in a loamy soil, doing well on limestone[]. Prefers some chalk in the soil but it is apt to become chlorotic if too much is present[].
In areas near the limits of its climatic tolerance, this species grows and flowers well when placed against a sunny wall[, , ].
The variety ilicifolia is widely cultivated as an ornamental in California because of its persistent, dark green, hollylike foliage[].
Trees are moderately fast-growing when young, though they slow with age. They often live more than 100 years in the wild[]. Heavy fruit crops are only produced periodically[].
The flowers are sweetly scented[].
Most members of this genus are shallow-rooted and will produce suckers if the roots are damaged[].
This species is notably resistant to honey fungus[].

Edible Uses

Fruit - raw, cooked or dried for later use[, , ]. A pleasant tart taste[, ], it is considered by some people to be a great delicacy[]. A thin, slightly acid, astringent flesh[]. The fruit can be mixed with lemon to make a sauce[]. The dark red to purple or blue-black, obovoid or ellipsoid to globose fruit only has a very thin flesh, it is about 12 - 25mm in diameter and contains one large seed[, , ].
The fruits from some forms of this species (formery distinguished as Prunus lyonii) are said to compare favourably with the cultivated sweet cherries[, ]. They can be up to 30mm in diameter, with a thick sweet juicy flesh[].

Seed - raw or cooked[, , ]. The seed can be ground into a meal, leached to remove the bitterness and then mixed with flour to make bread etc[]. The seed meal can be leached by placing it in a basket and then pouring warm water over it[]. Do not eat the seed if it is too bitter - see the notes above on toxicity.

Medicinal

An infusion of the leaves, or of the bark and roots, has been used as a cough medicine[].

Although no specific mention has been seen for this species, all members of the genus contain amygdalin and prunasin, substances which break down in water to form hydrocyanic acid (cyanide or prussic acid). In small amounts this exceedingly poisonous compound stimulates respiration, improves digestion and gives a sense of well-being[].

Agroforestry Uses:

Holly-leaf cherry can be used to stabilize steep, erodible hillsides. The plants are easily propagated from seed sown in flats, open seedbeds, or directly onto the ground; if direct planted, seeds are often consumed by rodents. Seedlings grow best in full sunlight and porous soil, and will tolerate considerable abuse in handling. Once transplanted, it requires little maintainence. Transplants usually begin seed production within 2 years of setting out and subsequent volunteers are numerous. On relatively poor chaparral sites, transplants can reach heights and spreads 90 - 150cm within 20 years[].
The plant is often grown as a hedge in southwestern N. America[].

Other Uses

A green dye can be obtained from the leaves[].
A dark grey to green dye can be obtained from the fruit[].

The wood is heavy, hard, strong, close grained. Usually too small to be of commercial importance, it is used mainly as a fuel[, ].

Propagation

Seed - requires 2 - 3 months cold stratification and is best sown in a cold frame as soon as it is ripe[]. Sow stored seed in a cold frame as early in the year as possible[]. Protect the seed from mice etc. The seed can be rather slow, sometimes taking 18 months to germinate[]. Prick out the seedlings into individual pots when they are large enough to handle. Grow them on in a greenhouse or cold frame for their first winter and plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood with a heel, mid summer in a frame[, ].
Softwood cuttings from strongly growing plants in spring to early summer in a frame[].
Layering in spring.