Tenax vs Cookianum
Phormium tenax and Phormium cookianum are New Zealand flax species, and at a glance, they look similar, so it’s easy to mix them up.
The quickest way to separate them is to look at the leaf or the seed pods if in season.
Leaf attributes & size
Phormium tenax (harakeke)
Leaves are upright and stiff, often over 2 m tall once mature (the bigger of the two).
Grows in large, strong clumps.
Leaf tips are often straight or slightly bent.
Phormium cookianum (wharariki)
Leaves are drooping, softer, and arching, rarely over 1.5 m tall.
Generally looks looser and more graceful in habit, but smaller.
Leaf tips tend to flop over.
Flower or seed pod
Phormium tenax (harakeke)
Flower stalks are taller than the leaves (up to 4–5 m). The stalks look huge.
Flowers are usually red/orange.
Flowering season: usually spring–early summer, empty seed pods on stems visible through winter.
Phormium cookianum (wharariki)
Flower stalks are shorter or level with leaves. Next to each other, they look much smaller than tenax
Flowers are often yellow–green.
Flowering season: later, often summer–early autumn, sempty seed pods on stems visible through winter.
