(12 MAY 1835-25 NOV 1902)
| | +---James Trethewy
| | +---Richard Trethewy (ABT 1665-JAN 1741)
| | +---John Trethewey (ABT 1690-)
| | | +---Ann Martyn 
(ABT 1666-JUN 1738)
| | +---John Trethewey (ABT 1720-)
| | | | +---Phillip Mellow (ABT 1660-JAN 1711)
| | | +---Temperance Mellow (ABT 1690-MAY 1765)
| | | +---Jane ?
| | +---Richard Trethewy (ABT 1762-MAR 1836)
| | | | +---Joseph Grose
| | | +---Jane Grose (ABT 1724-)
| | | +---Jane ?
| +---Ann (Nancy) Trethewey (ABT 1807-)
| +---Ann Rickard (ABT 1779-)
George Trethewey (ABT 1874-)
| +---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 ?
| +---John Trethewey (ABT 1785-)
| | +---Charity Strangeman (1756-)
| +---John Trethewey (ABT 1810-05 NOV 1885)
| | | +---Richard Whetter
| | +---Mary Whetter (ABT 1789-JUN 1828)
| | +---Mary Bullon
+---Ann Trethewey (ABT 1839-10 AUG 1901)
| +---John Goodge (-BEF 1851)
+---Ann Goodge (ABT 1813-05 MAR 1890)
+---Jane Yelland (ABT 1773-)