[1] LSJ has no entry for xamai/leon, but the plants appear under the entry for xamaile/wn. The variant spelling here in the Suda may have been adopted to distinguish the plant from the animal of the same name (chi 69). The name was applied by the Greeks to plants whose leaves changed color, specifically the pine thistle or Atractylis gummifera (also xamaile/wn leuko/s) and Cardopatium corymbosum (also xamaile/wn me/las).
[2] Nowadays this is better-known by the transliteration of its Greek name: "chamomile" or "camomile", although it is probably to be identified with Roman or garden chamomile (Anthemis nobilis) used today in hair dyes rather than with German chamomile (Matricaria recutita) which is used in tea. The ancients probably used it as a cure for jaundice; see Pliny, Natural History 22.53. The name xamai/mhlon from "earth" (xamai/) and "apple" (mh=lon) -- compare the French pomme de terre, potato -- was probably applied because the plant gives off a faintly apple-like scent.