2 August 2026
How many seed capsules can you think of that have “hitchhiker” hooks?
#1. I was puzzled by the acorn cup, pictured above, because I don’t know of any native northeastern oaks that have these hooks. The acorn is from a non-native Turkey oak (Quercus cerris) from southeastern Europe including Turkey. It was planted in Schenley Park at the top of the Serpentine Road more than 100 years ago.
#2. Those hooks reminded me of common burdock (Arctium minus), another non-native plant from Europe. The oak is not invasive but common burdock is.
#3. For native plants with hooks I thought of the sweetgum (Liquidambar styraciflua) seed ball even though its spikes are not very hooked at the tips.
When the sweetgum ball dries out it is woody and spiky and very bad to step on with bare feet. Each sweetgum spike contains 1 or 2 seeds.
#4. These small hooked seed capsules are on a stem of small flowered agrimony (Agrimonia parviflora). Agrimony branches dangle across the trail near knee height and readily grab onto your pant legs. They are at least slightly aggravating.
Can you think of other examples? If so leave a comment.
I think of burrs of all types, although I don’t know any of the names. I recall being covered with them after a snowy hike years ago. What a chore to pick them all off!
How about Chinese forget-me-nots?
Also, your article caused me to remember an encounter with a “jumping cactus” in the Arizona desert. It shot out a barbed burr that stuck my fingers together. The only way I could get it off was by yanking it with a pocket comb. Ouch!!!
as the article says ‘pet owners fear the foxtail’
https://ucanr.edu/blog/over-fence-alameda-county/article/foxtail-fearsome-weed-many-names
Beggar Ticks.