Platycerium × siamense, a quality staghorn fern hybrid for garden display

Platycerium is a popular ornamental fern genus. To enhance its aesthetic quality, P. angolense (syn. P. elephantotis) and P. willinckii were hybridized using a pair-prothallus method. Of 25 prothallus-pairs, only 1 plantlet was morphologically identified as the interspecific hybrid. The F₁ hybrid, which was named Platycerium × siamense Phuangkaeo, showed better quality than both parents. For the leathery fertile frond, it was wider than the parents (75.8 cm compared with 27.2 and 45.4 cm). The deep dichotomous and hairy lobe was somewhat similar to P. willinckii, but the frond, which was more hairy than P. willinckii, had a silvery appearance. The degree of branching was somewhat intermediate (2-3 times) of the parents (0 and >5 times). The (non-fertile) shield frond was broader than the parents (38.3 cm compared with 14.2 and 18.8 cm) and was persistent, unlike those of both parents that had a period of dry appearance. Besides its superior aesthetic quality, the hybrid robustness makes it more desirable for cultivation and garden display than the parents. The hybrid has been able to produce soral patches with non-fertile spores for the past 5 years. Fortunately, the hybrid produces a number of lateral shoots (plantlets) suitable for commercial propagation.