I don't have this book yet, but dead plants as ReTe? Fossilized plants maybe, or semi-composted, but craft magic uses ReHe to craft wood which has already been cut to lumber, making it pretty dead as a plant...
That Giant Wicker Basket appears to use a base that isn't defined. I don't see a ReHe guideline for Base 15 that fits.
Magi of Hermes also establishes teleporting guidelines consistent with Rego Corpus (see Persephone of Tytalus), ReTe(He) base 5 will move a target instantaneously 50 paces. There aren't any published guidelines that teleport, except for the ReCo and ReTe guidelines, but allowing casting requisites makes a lot of sense. I suppose extending it to ReHe might make some sense, but I don't like it, but can't fully articulate why, yet.
All solid objects are generically Terram to some extent, which is why Invisible Porter, Sling of Vilano, etc. work on items other than large rocks.
Still, wood is also and always Herbam; that's why a PeHe will destroy a 20-year-old wood door despite there having been no living component to it for decades. Also, how Dance of the Staves and Ward Against Wood (both ReHe) work - wouldn't be very useful to have a spell that only worked on weapons made from living plants.
Hmm, it looks like the Wicker Basket spell just took the ReCo guideline and didn't interpolate it for Herbam. I'm still not sure which is wrong, the Basket or the new guidelines.
I should note there are eight spells/item effects I see that use the "old" guideline that would be affected by this change:
Move Gigantic Wicker Basket (ReHe35) MoH43
Fill the Well (ReAq60) HP23
Instantaneous Transportation of the Captured Beast (ReAn40) HP129
Launch the Distant Vessel (ReHe55) HP58
Pages of the Unfinished Story (ReAn45) HP90
The Demand Of The Forgetful Scholar Soothed (ReAn40) Cov100
The Demand Of The Frustrated Scholar Soothed (ReAn40) Cov100
The Endless Well (ReAq60) HP44
So saying just change the spell may be an answer, there's more than one spell this affects.