Story Identification: colonists on a planet where the wheat is crystalline

I read a story back in the early 90s about a group of colonists who landed on a planet where the wheat (or wheat-like equivalent) is some kind of crystalline plant. The colonists face starvation until one of them figures out how to process the wheat.

I think it was by Asimov but so far I haven't found it by looking for his works.

I also cannot remember if it was a novel or a short story.

Answer

This is "The Green Book", a 1986 novel by Jill Paton Walsh

It features crystalline plants (which you can see on the book cover) and a starvation theme;

Refugees from the dying planet Earth, they, along with other ships, have been sent into space in the hope that some of them will survive to continue the human race. But the success of Shine remains doubtful as crops fail and provisions brought from Earth dwindle.

Even the excitement surrounding the hatching of the giant moth people from the "boulders" in Boulder Valley doesn't make the group forget the hopelessness of the situation. It isn't until Pattie and her sister Sarah make an important discovery that survival becomes a certainty.

The book contains a couple of quite vivid descriptions of the vegetation:

One morning when we woke up they were all sick, lying in a heap in a corner of their hutch, with sad cloudy eyes. And by the next day they were all dead. Sarah said they died of homesickness; Father thought they might have caught some kind of virus; most people thought they had been killed by eating the crystalline plants. The chickens were all right; and they had eaten only Earth-grown grain.

Eventually, the children realise that despite the grains being like glass beads, they can be crushed and ground like flour:

But Sarah said, "I'm going to try, I'm going to try, I'm going to try!" She stole a handful of the glass beads, and rubbed them between two stones, and they fell easily into a dry white powder that smelled good. She sent Pattie for a ladle of lake water, and mixed a dough, and rolled it out thin, and made a pancake, and cooked it on the fire. Then, when it looked done, she broke it into four pieces, and gave one to Pattie and one to Joe, and bit into one herself, leaving Father's share in the pan.

Oh, it tasted good! We ate it in three bites.