(1862-1934)
+---Wilburt Trethewy
| | +---James Trethewy
| | +---Richard Trethewy (ABT 1665-JAN 1741)
| | +---John Trethewey (ABT 1690-)
| | | +---Ann Martyn 
(ABT 1666-JUN 1738)
| | +---Joseph Trethewy (ABT 1735-DEC 1816)
| | | | +---Phillip Mellow (ABT 1660-JAN 1711)
| | | +---Temperance Mellow (ABT 1690-MAY 1765)
| | | +---Jane ?
| | +---John Trethewey (ABT 1764-JAN 1834)
| | | | +---John Rickard
| | | | +---Jonas Rickard (ABT 1705-)
| | | +---Caroline Rickard (ABT 1734-)
| | | +---Honour ?
| | +---Benjamin Trethewey (ABT 1802-BEF 1861)
| | | +---Charity Strangeman (1756-)
| | +---Richard Trethewey (19 NOV 1829-18 APR 1897)
| | | | +---Richard Thomas (ABT 1763-)
| | | +---Elizabeth Thomas (ABT 1808-)
| | | +---Mary ?
| +---Naomi Jane (Jennie) Trethewey (18 AUG 1859-1935)
| | +---John Warne
| +---Naomi Warne (ABT 1834-1912)
| +---Mary ?
+---Wilfred Roy Trethewy (14 OCT 1922-MAR 1996)
Linda Trethewy
+---Arlie Eileen Martin