FERNS:

Pteridophyte Phylogeny Group (Wikipedia)

GYMNOSPERMS:

The Gymnosperm Database

EUDICOTS:

Apodanthaceae - The Parasitic Plant Connection (D. Nickrent)

Asteraceae - Capitulum

Balanophoraceae - The Parasitic Plant Connection (D. Nickrent)

Balsaminaceae - D. Pitman (Mr. Impatiens)

Boraginaceae, subtribe Amsinckiinae - M.G.Simpson/Amsinckiinae Working Group

Convolvulaceae (Cuscuta) - The Parasitic Plant Connection (D. Nickrent)

Cynomoriaceae (Cynomorium) - The Parasitic Plant Connection (D. Nickrent)

Cytinaceae - The Parasitic Plant Connection (D. Nickrent)

Fabaceae - Legume Taxonomy Working Group

Hydnoraceae (Hydnora) - The Parasitic Plant Connection (D. Nickrent)

Krameriaceae (Krameria) - The Parasitic Plant Connection (D. Nickrent)

Lauraceae (Cassytha) - The Parasitic Plant Connection (D. Nickrent)

Lennoaceae - The Parasitic Plant Connection (D. Nickrent)

Loranthaceae - The Parasitic Plant Connection (D. Nickrent)

Malpighiaceae - W.R. Anderson, C. Anderson, C.C. Davis

Misodendraceae - The Parasitic Plant Connection (D. Nickrent)

Mitrastemonaceae (Mitrastema) - The Parasitic Plant Connection (D. Nickrent)

Moringaceae - M. Olson

Olacaceae s. lat. - The Parasitic Plant Connection (D. Nickrent)

Opiliaceae - The Parasitic Plant Connection (D. Nickrent)

Orobanchaceae - The Parasitic Plant Connection (D. Nickrent)

Rafflesiaceae - The Parasitic Plant Connection (D. Nickrent)

Santalaceae s. lat. - The Parasitic Plant Connection (D. Nickrent)

Schoepfiaceae - The Parasitic Plant Connection (D. Nickrent)

Verbenaceae - Verbenaceae Working Group

Viscaceae - The Parasitic Plant Connection (D. Nickrent)

OTHER SITES OF INTEREST:
The Parasitic Plant Connection (D. Nickrent)