It would probably be easier to list the types of plant he didn't inspire.

• Crassula ovata 'Gollum'
• Crassula ovata 'Hobbit'
• Eryngium 'Blue Hobbit'
• Helianthus annuus 'Orange Hobbit'

Epimedium 'Galadriel' - “A new and, as they say, improved version of Epimedium x rubrum, Galadriel has the usual heart-shaped red-tinged leaves, above which float in spring very striking two-toned red and white starry flowers, larger than the species and with little in the way of yellow at the centres.” [https://paddockplants.co.uk/perennials/epimedium-galadriel ]

Fuchsia 'Galadriel' “is a vigorous, upright to open, deciduous shrub with ovate, toothed, dark green leaves, and, throughout summer, flowers with creamy-white sepals and single, red corollas.” [https://www.shootgardening.co.uk/plant/fuchsia-galadriel ]

Galanthus 'Galadriel' “is a bulbous perennial to 15 cm with relatively broad, grey-green leaves and solitary, nodding, white flowers, the inner petals marked with a green, inverted Y, in late winter and early spring” [https://www.rhs.org.uk/Plants/315581/Galanthus-Galadriel/Details ]

Hemerocallis 'Galadriel's Ring'. Introduced 2020. “In Tolkien's trilogy there were three Elven rings and Galadriel possessed one of those three rings. This daylily flower also has three rings. The pale yellow flower has three rings on the petals. The petal edges are ruffled and the ruffle colors change from rose to pink and then a gold outer edge.” [http://www.kendigdaylilies.com/CatalogDetail/GALADRIEL_S_RING ]

Iris 'Galadriel's Ring'. Introduced 2008 [https://davesgarden.com/guides/pf/go/170635/ ]

Primula auricula ‘The Lady Galadriel’ [https://www.hillviewhardyplants.com/product/primula-auricula-the-lady-galadriel-a/ ]

Iris 'Eye of Sauron' with “Medium steel violet blue standards, paler grey violet edge and veins up midrib; medium steel violet blue falls, ecru rim, large dark charcoal plum spot veined wide tan to white 2/3 of way out, white dart bisects spot at end of beard”. [https://garden.org/plants/view/536988/Standard-Dwarf-Bearded-Iris-Iris-Eye-of-Sauron/ ] It actually looks quite nice!

Someone else loves both Tolkien and hostas as much as I do - as a result there are many hybrids inspired by the Tolky oeuvre, such as:

• 'Gandalf' (medium green/yellow leaves, reg. 1999)
• 'Mithril'(medium green)
• 'My Precious' (Miniature, medium green/yellow)
• 'Shadowfax' (Yellow)
• 'Academy Celeborn' (blue/green, 2004)
• 'Academy Lothlórien' (yellow, 2004)
• 'Academy Mallorn' (medium green, 2003)
• 'Academy Weathertop' (medium green, 2000)

From plantsgalore.com

I just assume there are lots of roses with Tolkienish names. Because there are lots of named roses. Indeed, so many quirky and literary ones that I looked through a whole bunch of roses with references to Shakespeare, Hardy and Ellis Peters (Brother Cadfael), but nothing so far with Tolkien!

Oh well, there are candidates. Such as:

• Rosa Fellowship ('Harwelcome'). Floribunda, orange flower. davidaustinroses