Maybe you're typing too much into the search box, or maybe you're still spelling them as two words instead of one. Here's what I get when I search for acer bloodgood:
http://garden.org/plants/searc...
And here's the result for acer fireglow:
http://garden.org/plants/searc...
Or you can search for just acer, click on "Click here to view all plants in the genus: acer," and then click on the letters at the top to find them alphabetically:
http://garden.org/plants/brows...
