The species of Taxus are more geographically than morphologically separable; and they were all treated by Pilger (1903) as subspecies of Taxus baccata. All species are poisonous; most contain the anti-cancer agent taxol; and a study of heartwood constituents of Taxus baccata, Taxus brevifolia, Taxus cuspidata and Taxus floridana found them to be chemically almost identical. However, the vast ecological amplitude displayed by the various described species (over 60° of latitude and an impressive temperature and precipitation range) suggests that they are, in a meaningful sense, true species. Detailed study of the genus (not neglecting the cultivated representatives), including extensive fieldwork, is much needed and long overdue[].

Common Name: Mexican Yew

General Information

Taxus globosa is an evergreen shrub or a tree that can grow up to 4.6 metres tall[], with specimens up to 15 metres reported in the highlands of Guatemala[].
The tree is sometimes harvested from the wild for local use as a food and source of wood. It is a potential source of the anticancer drug 'taxol'.
Some interest has been shown by pharmaceutical companies in the medicinal properties of Taxus globosa. There is no evidence of active exploitation for that purpose. The principal threat to this species is the ongoing over-exploitation of the montane cloud forests throughout Mexico and Central America. The plant is classified as 'Endangered' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

All parts of the plant, except the flesh of the fruit (actually an aril), are potentially highly poisonous. They contain the alkaloid taxine and , if ingested, can cause nervousness, trembling, slow pulse, pupil dilation, difficult breathing, abdominal pain, vomiting, diarrhoea, weakness and convulsions - in larger doses it can be fatal, having a paralyzing affect on the heart[, , , , , , ].

Botanical References

Range

C. America - Honduras, El Salvador, Guatemala, northern, central and southern Mexico

Habitat

Low and middle tree layers of montane forest, oak forest, and pine-oak forest, where it is considered as a indicator species for cloud forest. It shows a strong preference for moist and shaded ravines. Found at elevations from 1,000 - 3,333 metres[].

Properties

Conservation Status	Endangered
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	4.00 m
Growth Rate	Slow
Pollinators	Wind
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Taxus globosa is moderately cold hardy, tolerating occasional, short-lived temperatures falling to between -12.1°c and -6.7°c[].
Plants are very shade tolerant[], though they can also succeed in full sun. They thrive in almost any soil, acid or alkaline, as long as it is well-drained[, ]. Succeeds in dry soils. Plants grow best in a position sheltered from cold, dry winds[].
This species produces the largest fruits (arils) in the genus[].
As with most other Taxus species, Taxus globosa is a potential source of anti-cancer drugs. However, its subpopulations are likely to be too small and scattered to make harvesting of wild plants commercially viable. Plantation cultivation would be the only viable and sustainable option[]
A dioecious species, both male and female forms must be grown if fruit and seed are required.

Edible Uses

We have no specific information for this species, but the fruit (a fleshy aril) of all members of the genus should be edible. The following is a general description.
Fruit - raw[, , , , ]. Very sweet and gelatinous, most people find it delicious though some find it sickly[]. A number of people who like the flavour do not like the texture which is often described as being 'snotty'[]
All other parts of this plant, including the seed, are highly poisonous. When eating the fruit you should spit out the large seed found in the fruit's centre. Should you swallow the whole seed it will just pass straight through you without harm. If it is bitten into, however, you will notice a very bitter flavour and the seed should immediately be spat out or it could cause some problems. The fruit is a fleshy berry about 10mm in diameter and containing a single seed[].

Medicinal

As with most other Taxus species, Taxus globosa is a potential source of anti-cancer drugs[].

Other Uses

The bark is said to be rich in tannin[].

The heartwood is bright orange to brown, the thin band of sapwood is white. The texture is very fine and uniform; the grain straight or variable; lustre is rather high; it is free of an distinctive odour or taste. The wood is hard, moderately heavy, stiff, and elastic. It has long been used in Europe for making bows[].
Locally used for fence posts[].

Propagation

Seed - can be very slow to germinate, often taking 2 or more years[, ]. It is best sown as soon as it is ripe in the autumn when it should germinate 18 months later. Stored seed may take 2 years or more to germinate. 4 months warm followed by 4 months cold stratification may help reduce the germination time[]. Harvesting the seed 'green' (when fully developed but before it has dried on the plant) and then sowing it immediately has not been found to reduce the germination time because the inhibiting factors develop too early[]. Prick out the seedlings into individual pots once they are large enough to handle and grow them on in pots in a cold frame. The seedlings are very slow-growing and will probably require at least 2 years of pot cultivation before being large enough to plant out. Any planting out is best done in late spring or early summer, after the last expected frosts[].
Cuttings of half-ripe terminal shoots, 5 - 8cm long, July/August in a shaded frame. Should root by late September but leave them in the frame over winter and plant out in late spring[]. High percentage[].
Cuttings of ripe terminal shoots, taken in winter after a hard frost, in a shaded frame[].
Layering