Dioon spinulosum or Giant Dioon is one of the tallest and easiest to grow cycas.
It is a living fossil from the Mesozoic era, found in the rainforests in Mexico where it is endangered due to its restricted habitat and deforestation.
This is the fastest growing cycad.
Grows up to 1.5-3.5 m high in culture, 12 m in habitat. The trunk measures up to 30 cm in diameter.
The leaves are pinnate, 1.5-2 m long and radiate from the trunk. Each leaf has 150-250 leaflets. The leaflets are small, with marginal thorns and end in a sharp point.
Flowers are insignificant but the fruit is huge and can weigh 15 kg. Flowering occurs after 15 years for male plants and 17 years for female plants.
Seeds are used to produce flour (but recent studies have shown that all cycas contain dangerous carcinogens and neurotoxins).
Cycad, Giant Dioon, Mexican Dioon, Spiny Dioon
Dioon: from the Greek dis (two) and oon (egg) because the seeds are formed in pairs
Spinulosum: from the Latin spinula (small thorn)
In rain forests, on rocky slopes and hills
USDA zone 9-11, -4 °C for short periods of time
Sun, light, partial shade
Let the soil dry in between waterings
Resists poor and arid soil but regular fertilizing will result in better growth
- soak for 2 days in lukewarm water
- sow in light mix
- 30-35 °C
- germination time: 7 days to 6 months