Physic Nut

Scientific name: Jatropha curcas

IUCN Red List threat level: Least Concern

GPS Location: 17° 42′ ″ N, 64° 49′ ″ W

Observations:

1. Leaf Behavior
Physic Nut is deciduous, especially in dry or drought-prone conditions.

Leaves are broad, deeply veined, and typically 3–5 lobed.
Leaf drop is common in the dry season (January–March) or during extended droughts.
New leaf flushes emerge rapidly with rainfall or irrigation.

Observation Tips:

Monitor timing and extent of leaf loss, particularly in dry months.
Record leaf regeneration, noting color and rate of canopy recovery after rains.

2. Flowering
Flowers are small, yellowish-green, and produced in clusters (cymes) at the branch tips.

J. curcas is monoecious, bearing both male and female flowers on the same plant.
Flowering can occur several times a year, often peaking in the early wet season (April–June).

Observation Tips:

Look for small inflorescences at new growth points.
Track flowering frequency, and monitor for pollinator visits (mostly small bees and flies).
Note flower ratios (male vs female) as they vary by environmental conditions.

3. Fruiting
Fruits are green, oval capsules that turn yellowish or brown as they mature.

Each capsule contains three black seeds, which are toxic if ingested but rich in oil.
Fruiting typically follows flowering by several weeks and can occur two or more times per year, depending on rainfall.

Observation Tips:

4. Growth Habit
Grows as a woody shrub or small tree, usually 6–15 feet tall.

Very drought-tolerant, making it suitable for xeric landscapes, but it can spread aggressively in some areas.
Frequently used in hedges or erosion control plantings, but all parts are toxic if consumed.

5. Seasonal Pattern (St. Croix)