Ask Mr. Smarty Plants

"The mission of the Lady Bird Johnson Wildflower Center is to increase the sustainable use and conservation of native wildflowers, plants and landscapes."

That said, we won't recommend any species not native to North America.  Here is a rundown of the species you mention:

Anethum graveolens (dill) is not native to North America (native to Asia).

Boehmeria cylindrica (false nettle) is native to North America and not considered invasive.

Ruta graveolens (common rue) is native to southern Europe and Africa, not native to North America.

I'm not sure which species of Cassia you are refering to, but Cassia fistula (golden shower) occurs in Florida and, although it is not native (native to Asia), it is not considered invasive there.

Comandra umbellata (bastard toadflax) is native and not invasive as far as I can find.  It is hemi-parasitic; that is, even though it is green and photosynthesizes much of its food, its roots also attach to other plants growing nearby and acquire some of its food and water from them.

There are many species of plantains (Genus Plantago).  Among them, Plantago aristata (largebracted plantain), native to North America, and Plantago lanceolata (narrowleaf plantain), not native, are both on the Federal and State Noxious Weeds list.  I don't know which plantain you refer to, but there are many plantains that are native and not invasive or noxious.

You can find a list of native plants that are hosts for butterflies and moths of North America on our webpage.  On that page you can use the NARROW YOUR SEARCH option to select plants native to Nebraska and will have the best chance of thriving there. For instance, you will see that there are seven different species of Asclepias native to Nebraska that serve as larval hosts to monarch (Danaus plexippus) and queen (D. gilippus) butterflies.

You can find a list of List of Butterflies of Nebraska and by clicking on the butterfly species, you will find both larval and adult hosts for each species.

There is also a Nebraska Butterfly Association page with a Butterfly Gardening article with lists  of plants, both larval and adult hosts.  You can check the nativity of the plants by searching our Native Plant Database.  Still another website, Butterflies of Nebraska, has a list of plants that are hosts to butterflies, but they don't link the plants to a particular butterfly.  Most of the plants appear to be native to North America, but, again, you can check them against the Native Plant Database to be sure.

You can find numerous books on butterflies and butterfly gardening in our Native Plant Bibliography.  For instance, although its focus is on the South, Butterfly Gardening for the South (Geyata Ajilvsgi, 1991) is an excellent book with photos of many butterflies and information on their host plants.  There is also much information and photos of the plants that are recommended.

We do urge you to avoid using non-native plants and to, instead, use plants native to Nebraska in your garden. The natives are adapted to your environment and are more likely to thrive there using less water and fertilizer than non-natives.