parasitic plant id please

[rustylady]

How much has it grown since you first posted?

[Bill HH]

Please keep this to yourself we do not need another weed to worry about.

[green thing]

Its in 3 of about 30 celltrays not grown that much keeping it away from other trays

Would rather make people aware of it and the possible source
No point keeping quite about it's when it's already here.