(κάλαμος, Heb. קָנָה = Eng. ‘cane’)
The ‘reed like a staff’ (κάλαμος ὅμοιος ῥάβδῳ) which St. John used for measuring the temple of God (Revelation 11:1) was probably the arundo donax, which flourishes especially in the Jordan Valley, growing in marshy brakes to a height of 15 to 20 ft. and strong enough to be used as a walking-stick (Ezekiel 29:6-7, Isaiah 36:6). Being straight and light, this reed served also as the most convenient measuring-rod (Ezekiel 40:3; Ezekiel 40:5), and as a definite measure it was 6⅔ cubits long = about 9 ft. (Liddell and Scott, s.v.). The New Jerusalem was measured by an angel who had for a measure a golden reed (Revelation 21:15-16).
James Strahan.