A word I came across while reading up about prospective summer destinations in the mountains of Jämtland.
He hadde a gay surplys
As whit as is the blosme vp on the rys (Chaucer, Miller's Tale)
Chaucer would have meant blackthorn (or maybe hawthorn) in this case. Generally, "Rys" means twiggy, bushy, brushy material. The nearest one-word translation might be "spray" but that's itself a little bit old-fashioned now.
"Ris", "rys" or "rice" is a word that was common in Middle English but sadly has dropped out of standard modern English completely, though it still survives in some rural usage e.g. in parts of Scotland and the Orkneys.
In Swedish it's still a widely used word, reflecting a nation with much closer links to the forest. It's used in a great many contexts but perhaps especially about such very common sub-shrubs as bilberry, ling and dwarf-birch.
(In southern England the word survived longest when it was transferred to agricultural practices, for example to talk about the dry haulms of beans.)
Middle English Dictionary, rī̆s (n.(1)
Oxford English Dictionary, RICE, n.1 (Sign in with your library card to view)
Svenska Akademiens Ordbok, RIS, sb1
Definition 2 here is "grenvärk (på träd eller buske eller buskliknande växt) med många, jämförelsevis korta, mer eller mindre hopgyttrade grenar eller kvistar (stundom om själva grenvärket med bortseende från löv, blommor o. knoppar)" . Essentially this means: "stem-work (of tree, bush or bushlike plant) with many, relatively short, more or less agglomerated stems or nodes (sometimes the stem-work itself, setting aside leaves, flowers and buds).
This is helpful but it suggests the precision of a botanical description. "Ris" is a proper country word, invented by people who work with nature rather than make analyses of it.
"Risig" is typically used to comment on land that is difficult to walk on because covered in tough springy sub-shrubs.
But when I mentioned the word to my mum, the first thought that came to her was "Var snäll, eller smakar riset!" ("Be good, or taste the ris!"). My grandmother always kept a bilberry "ris" on the shelf that surrounded the hood above the kitchen stove (a place where you also kept boxes of matches and where you could dry cloths). It was a mainly symbolic instrument of chastisement, more commonly used for sundry domestic whiskings.
In both languages the word is homonymous with the word for one of the world's most important foodgrains. But "rice" in the latter sense derives from OF or Latin ("risa"), ultimately via Greek with analogues in Sanskrit and Dravidian. Whereas the spriggy word that I'm talking about here derives from common old Germanic (OE/ON "hris").
[Image source: http://konvaljen.blogspot.co.uk/2012/02/mitt-blabarsris.html]