rusty-back
noun
(Also rusty-back fern) any of several ferns with rust-coloured sori or scales on the fronds; (in later use) specifically Asplenium ceterach (family Aspleniaceae), a European fern which has alternately lobed, lanceolate leaves densely covered beneath with scales which become reddish-brown with maturity.
Origin
Late 18th century; earliest use found in William Withering (1741–1799), physician and botanist.
- primary cell
- primary cell wall
- primary colour
- primary constriction
- primary dealer
- primary education
- primary election
- primary endosperm nucleus
- primary evidence
- primary feather
- primary group
- primary health care
- primary industry
- primary instruction
- primary legislation
- primary market
- primary meristem
- primary mirror
- primary oocyte
- primary pit field
- primary planet
- primary poverty
- primary process
- primary production
- primary qualities