Platycerium coronarium
crown staghorn fern

How to recognise it

• The crown: tall, upright shield fronds split at the top into a ring of lobes, which gives the species its name; they stand like a tube and catch water themselves.
• Long, hanging fertile fronds: they fall from the top of the crown, commonly one to two metres on a mature plant, forking repeatedly into strap-like segments.
• A separate spore lobe: spores are not carried on the underside of the frond tips but on a kidney-shaped lobe that grows out of the fertile frond; on immature plants its shape is irregular.
• Telling it from ridleyi: P. ridleyi wraps its shields into a ball and holds stiffer fertile fronds up or out; coronarium raises an upright crown and lets long fronds hang.

Native habitat

Platycerium coronarium grows on large trees in lowland rainforest and monsoon forest from Thailand and Peninsular Malaysia through Singapore, Sumatra and Borneo to the Philippines. The upright shield fronds collect falling leaf litter, and the fertile fronds hang from the crown like ribbons. In Singapore and Malaysia it is a native plant seen on roadside trees.

Light

Bright, filtered light. It tolerates slightly less light than P. ridleyi, but in a dim room the shields stay short and the fertile fronds turn thin and green. Morning sun is fine; avoid midday sun behind glass.

Water and humidity

The upright shields form a funnel that catches water, so this species forgives more than P. ridleyi. Soak when the surface of the medium is dry. Growth is fastest above 60% humidity; below 50% the frond tips brown. Keep air moving and never let water stand at the bottom of the funnel for days.

Medium and mounting

Sphagnum with a little bark. This is a tall, heavy plant: choose a thick board with a secure hanger, and leave at least a metre of clear space below it for the fertile fronds. Pups can be separated once they have their own shield, or left in place to form a clump.

Temperature and seasons (temperate, indoor)

Ideal range 22–32 °C; it enjoys heat. In temperate homes it lives indoors year-round. Keep it above 12 °C in winter; below 10 °C the fertile fronds blacken. Reduce watering in low light and keep a fan running so the funnel does not stay wet.

Common problems

• Black frond tips: low humidity or fertiliser burn.
• Sour smell from the funnel: standing water and rot; tip it out and improve drainage.
• Only shields, no fertile fronds: too little light or nutrition; fertile fronds appear reliably on mature plants.
• New fronds smaller than old ones: roots have filled the board or the medium has broken down.
• An immature plant's spore lobe looks odd, multi-fingered or half-round: mature plants carry a complete oval spore lobe; immature ones show a transitional shape. Not a variation, not a growing problem — judge it on a mature plant.

Collector notes

Frond expression. Trade distinguishes the common form from the Philippine form (deeper-cut crown, broader and shorter fertile fronds) and various dwarf and thin-frond selections. None of these is a formally described variety. Judge by the number of forks, the length of the drop and the width of the fertile fronds.

Mother plant. Look for a complete, symmetrical crown, fertile fronds emerging evenly from the top, and, in clumps, heads of similar size.

Propagation. Coronarium pups, so divisions preserve a mother plant's expression exactly. Spore-grown plants vary and are the route to new forms; tissue-cultured plants are uniform. A staghorn fern this large deserves a documented origin.