1) Order equisetales 2) Plant order 
The Equisetales is an order of pteridophytes with only one living genus Equisetum (horsetails), of the family Equisetaceae. The fossil record includes additional extinct species in the Equisetaceae and the extinct families Calamitaceae, Archaeocalamitaceae and Phyllothecaceae. ...
(from the article `Sphenophyta`) ...scrambling or vinelike understory plants, 1 metre (3 feet) tall, with small, wedge-shape leaves; 2 families: Sphenophyllaceae and ...
[n] - lower tracheophytes in existence since the Devonian
order Equisetales noun lower tracheophytes in existence since the Devonian