P. alata, P. x decaisneana, P. phoenicea and P. quadrangularis are often easily confused. See below and also see comparisons here.

Image © 2010 Stephen Gray

Name	Mature foliage	Flower	Ripe fruit
P. alata - quite like P. quadrangularis but smaller flowers. A very variable species.	2-4 petiole glands per stem. Stipules 1-2cm long by 0.3-1cm wide. Single lobed ovate leaves.	Flowers 10-12cm wide with neat corona filaments. Sepals and petals red inside & green out.	Fruit ovoid, 10-15cm long by 5-10cm wide, bright orange or yellow when ripe.

 

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Image © 2012 Martine Sanchez

Name	Mature foliage	Flower	Ripe fruit
P. x decaisneana - (P. alata x P. quadrangularis) often mislabelled and sold as P. quadrangularis. There are probably a number of clones of this cross.	4 glands on 90% of the stems. Stipules 15mm long by 6mm wide. Large ovate leaves.	Heavy flowers 10-13cm, corona filaments a bit scruffy at the end compared with alata. Sepals and petals red inside & sepals green out & petals red out.	Fruit egg shaped up to 18cm long, dull orange when ripe.

 

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Image © 2012 João Franco

Name	Mature foliage	Flower	Ripe fruit
P. phoenicea. Often known as P. alata 'Ruby Glow'. Sometimes will not set fruit with caerulea. All the others listed here will easily.	2 bright yellow petiole glands near the leaf make ID easy. Stipules 10-12mm long by 3-4mm wide. Large ovate leaves.	Flowers 11-13cm. Petals brick red outside & rich purple inside. Neat corona filaments. Sepals shorter than petals.	Fruit large ovate, up to 13cm long & 8cm diameter, yellow when ripe.

 

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Image © 2012 Marcel Böhrer Stuttgart Botanical Gardens.

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