Dianella longifolia R.Br., Prodr. Fl. Nov. Holland.: 280 (1810);
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E. & S. Australia as per POWO;
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Dianella longifolia from California-GS28052023-1: 5 high res. images.
Dianella longifolia, Perennial herb with linear grass-like leaves and blue flowers on long peduncles. Clicked from Union City, California on 27-5-2023.
How is it differentiated from other species.
https://www.smgrowers.com/info/dianella.asp
https://www.australianplantsonline.com.au/blog/post/best-dianella
https://www.ozbreed.com.au/plant-ranges/dianellas/
this plant had very narrow grass like leaves, barely 3-4 mm wide, the species widely in cultivation D. tasmannica has leaves more than 1 cm wide, In D. revoluta leaves are folded, not in this case, even D. caerulea has broader leaves. This seemed closest match.
Dianella revoluta R.Br.
Appears close as per images at
https://en.wikipedia.org/wiki/Dianella_revoluta
https://keys.lucidcentral.org/keys/v3/scotia/key/Plants%20and%20Fungi%20of%20south%20western%20NSW/Media/Html/Dianella_revoluta.htm (Dianella revoluta differs from Dianella longifolia ssp. longifolia and Dianella porracea in that the anthers are brown to almost black, and the leaf edges are curved or rolled down.)
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References:
POWO
https://en.wikipedia.org/wiki/Dianella_revoluta
https://keys.lucidcentral.org/keys/v3/scotia/key/Plants%20and%20Fungi%20of%20south%20western%20NSW/Media/Html/Dianella_revoluta.htm