Trunks 2–8 m tall; bark grey-black, scaly. Leaves fascicled at apex of stem, 1-pinnate; petioles 10–20 cm long, with spines along each side; leaflets 60–150 pairs, leathery, 10–20 cm × 4–7 mm. Pollen cones 30–60 × 8–15 cm, microsporophylls 3.5–6 × 1.7–2.5 cm. Megasporophylls 14–22 cm long, densely tomentose; ovules densely pale brown tomentose. Seeds (3–)4–5 × 2.5–3.5 cm, orange to red.10
Uses in TCM—seeds: stanch bleeding with astringent, unblock the meridians, promote digestion, pacify the liver and reduce blood pressure, suppress cough and dispel phlegm; flowers: regulate qi and dispel dampness, activate blood and stanch bleeding; leaves: regulate qi and activate blood, resolve stasis and relieve pain, disperse swelling and remove toxin. Recommended dose: seeds 9–15 g, flowers 15–60 g, leaves 9–15 g.2,11,12
In 2009, a middle-aged man presented with severe vomiting, dizziness and abdominal pain after taking the seeds of C. revoluta. He improved with supportive treatment and was discharged the next day.
Cycasin can be detected by GC-FID. β-Methylamino-L-alanine can be detected by LC-MS/MS.13,14