SureAI

I don't understand the alchemy system in Enderal. I stepped up to an Alchemy table in Glimmerdust cave and didn't understand what I could do or couldn't do. I thought I wanted to make a health potion but there was no list of ingredients . All that was shown in the right-hand pane was Blue Malphas flower and wheat. I have been gathering everything I can, so I think I have plenty of ingredients to choose from.

Do you need a recipe...like you do for a hunter's long bow or something like that?

You need a recipe, either buy one or learn one from experimenting. When you click on the alchemy table, you will see on the left "Ingredients" and below that a list of recipes you already know. On the right is the list of ingredients you are carrying. The recipes you can make (based on the ingredients listed on the right) are shown in white, the ones you lack ingredients for are grayed out. So, if Fortify Health is shown in white and you click on it, on the right side will probably be shown Blue M Flower & wheat. You have to click on each ingredient to select it, so you click on each of those, then hit "R" (if using a PC keyboard) to brew the potion. You can experiment with different ingredients to learn new recipes.

OK, now I'm starting to get it. Early morning here--no time to try it out but it makes sense. Thanks for the help.

another artefact to be aware off.....you only have visibility of the alchemical properties if you 'eat' the raw ingredient. After that, you can unlock the other properties during character leveling 'in the strange place'.
I was not aware that recipes existed.....
In general, the impact of alchemy has been substantially nerfed from Skyrim....happy concocting!
Truth

I must correct myself, you can't buy or find recipes, just learn them. For example (recipe follows)

[+]

Aeterna Ears, Juniper Berries, and Spider Eggs all have 2nd, 3rd or 4th level effect of Fortify Archery. So if you can only see the 1st level effects (by eating them and no advanced alchemy talents) you won't see "Fortify Archery" in your list of possible potions.

However, if you select 2 or 3 of the ingredients I mentioned and click R to create a potion, Fortify Archery will now appear in the list of potions you can create, so you have "learned" the recipe, although I don't think Enderal actually uses the term "recipe" but just calls it a list of potions, and by experimentation you have learned higher level effects of those ingredients.

I think of this as a recipe, because, for example, if you have a long list of ingredients in your inventory, click on an alchemy table, and then click on a particular potion shown in white, it will automatically show the ingredients which can be selected to make that potion, so to me that is a "recipe."

So, if you know the effects of the ingredients, and you have 2 or more ingredients in your inventory with the same known effects, it will show on the left side of the alchemy the name of the potion (in white) that can be made. If you have previously made a potion but don't have 2 or more of the necessary ingredients in your inventory, it will show the name of the potion in gray. And if you don't have 2 or more of the matching ingredients AND you have never made a particular potion, it won't be shown at all.

I've probably made this more complex-sounding than it really is.

To be honest, I always found it easier to just spam three ingredients at a time until I found all their effects. If I missed the first effect I just ate and saw what it was. With enough income and patience keep buying out the apothecary's ingredients and just mass all the materials together. You'll get your money back trust me. Once you learn the high grade potions you can just sell it back for profits. Think of it as a long term investment with viable returns.