Amaryllis belladonna , aka "Belladonna Lily", "Naked Lady" Reliably blooms in July and August, when very few other bulbs perform. Needs little care and is extremely "unfussy'. Drought tolerant. Is best in full sun, but does not mind a bit of shade. Needs little or no fertilisation. Clump size increase quite quickly. Perfect for under planting a shrub or small tree, in an area where you would rather not put too much or any effort into. Reliably hardy for our USDA 7b/8a zone - it's been in the garden without any winter protection for the past 5 years. The leaves stay healthy until first frost, and are never tatty or untidy. Best of all, I love the flowers.
Light bulbs, so I can work at the computer in the evenings ;-)) Otherwise, maybe Bluebells (Hyacinthoides non-scripta), for the extensive blue drifts on the woodland floor in May.
Probably camas (Camassia), easy and naturalistic here in its native region. Flowers do go over quickly and the leaves are apt to flop when not supported by grass. The amaryllis, which I also grow and have in bloom right now (in a warm nook) can be sporadic with flowering and have its foliage damaged by frost here in the North. A South African plant, it thrives best in Californian conditions of hot dry summers and mild, damp winters.
The key to amaryllis is a very well drained soil. The foliage dies down in the fall. But I agree, flowering is best on summers with prolonged hot spells. But the large clump at the base of our crab apple tree flowers very well every year. Another bulb I like - and they are flowering right now - are the Colchicums. Again, easy care - just grow them in the right positions and leave them to their own devices. They flower soon after the Amaryllis has finished with their display, which is handy. Their foliage appear earlier in the season then, dies down by mid to late summer. The flowers emerge in September/October without any of the foliage around.
>The foliage dies down in the fall< Foliage of Amaryllis belladonna appears in fall-winter, remains over winter and dries up the following spring-summer.
