This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The roots of many clematises are knotted, like as appear the roots of the grape vine when attacked by Phylloxera. The plants so attacked dwindle away in a year or two Professor Riley decides it not to be the work of a Phylloxera, but of another insect, an Anguillula. Besides this, some species are attacked by a borer allied to that which attacks the peach tree; that is an Aegeria.
There is another, fungus disease apparently, which is a fearful scourge on Clematis Jack-mani, and which keeps it always scarce.