Once established, Hellebores can take fairly dry shade - the leaves are attractive in the spring-to-winter period, then you cut them off when you see the flower buds start to grow so you can clearly see the flowers. New leaves will come up after the flowers are done. It WILL give you another winter flower under there, but.... They can take morning sun, but don't like PM sun. Mahonia will take shade, and dryness - you might have to eventually do an annual 'rejuvenation' prune to keep the height to what you want. Indian Hawthorn will take dry shade, as will Carolina jessamine. Delosperma (ice plant) is another possibility. Lamb's ears will do around the edges, although they may spread out into the lawn. Snow-In -Summer is another one for dryness. Penstemons, Dusty Miller, Blue fescue, some Euphorbias, Agastache (maybe too tall), sedums and Wild ageratum can all take at least part shade and dryness. The Wild ageratum is a rampant spreader in good garden conditions, but is better behaved in difficult situations. Mondo grass is another possibility, as is acanthus. The naturalizing cyclamens will also do, once established. SOME ferns will take dry shade - I am not that up on ferns, so will leave it for you to check out. Also, some of the sedges will take dry shade. And ALL of these will need watering until they are established, for however many days, weeks or months that takes.

If there's such a thing as a yellow impatiens, you might try that but 2 20W fluorescent lamps really put out very little light, so you're not going to have a wide range of options unless this is supplemental lighting in a spot that gets a fair amount of natural light to begin with. Since it's more specific to that forum than this, you might try the house plant forum, too.

They can form a large underground tuber like a dahlia, and so survive dry conditions to re-grow when things are better. They also self-seed like mad, and quickly, so watch them!

I also have only an eastern window in my living room. I have a furniture-quality shop light over a big shelf of cacti and succulents, and they are all growing outrageously with 2 T-8 fluorescent bulbs. In another corner, I have a can light mounted to the wall with a 75W equivalent LED flood bulb illuminating a big red Chinese evergreen. It's growing like it's on fire. On a table under that plant, I have an identical can light mounted to the wall with the same kind of bulb. Several sansevierias, an African violet, and a small peperomia are thriving with the light from that bulb.