Dahlia tubers as food

I tried eating the tubers of a Dahlia I found growing wild in a suburb of Wellington, New Zealand. I am not sure what species or variety it is, Dahlia coccinea x pinnata is reported to grow wild in New Zealand (1), it seems most likely to be this, photos below, let me know if you know. Both Dahlia coccinea and pinnata are edible cooked (2)  so it is safe to assume any cross between them is too.

The tubers are available in winter, I had to leave a marker in summer to find them as it goes dormant for winter so tubers can be hard to find. The plant produces an abundance of good sized tubers.

I tried them raw, they are crunchy like an apple with a slight taste of uncooked potato, but basically bland in flavor. I also boiled them. They remain crunchy after boiling with very little flavor, much like potato in taste but very different in texture. After prolonged boiling they get a bit softer but are still crunchy. I would say they have a slightly coarse texture, they also leave the mouth slightly dry I find, but they are basically okay.

I found them better roasted for 20-30 minutes, luscious in texture and more tasty, though still hard to describe.

Based on eating them once I would say they are not quite as good as more well known root crops, though a taste could possibly be acquired for them, they have been a traditional part of the diet in parts of South America (2). The fact that they are perennial, compete with weeds and require little or no care may still make them a worthwhile crop overall.    

The skin is sometimes reported to taste bad, I did not find this but it is a bit tough and can be slightly fibrous. 

The flowers of some Dahlias are also reported edible (3) these ones had little flavor but are colorful and good to eat.  

References.

1) New Zealand Plant Conservation Network. 

https://www.nzpcn.org.nz/flora/species/dahlia-coccinea-d-pinnata/

2) Food Plants in the Americas: A Survey of the Domesicated, Cultivated and Wild Plants Used for Human Food In the Americas. Brian Kermath. 2018.

https://www.academia.edu/1139225/Food_Plants_in_the_Americas_A_Survey_of_the_Domesticated_Cultivated_and_Wild_Plants_Used_for_Human_Food_in_North_Central_and_South_America_and_the_Caribbean

3)The Encyclopedia of Edible Plants of North America. Francis Couplan. 1998.