The Amateur Botanist by Francis UnderwoodThe Amateur Botanist

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Rhode Island’s “Undiscovered” Plants
Photo credits: Francis Underwood

Plant species new to the flora of RI are constantly being discovered around the state. Some of these are desirable plants and others are listed as invasive by IPANE.  Many of these are not included in the Vascular Flora of RI by Gould, et al, or in Gil George’s RI Botanical Survey Checklist. The sixteen species listed below represent some of these plants.

American BladdernutStaphylea trifolia L., American Bladdernut
In May, 2005, Betty Allen, Kathy Barton and I were walking some protected land in Lincoln when we spotted an unusual flowering shrub. Using Newcomb’s Wildflower Guide we determined it to be Staphylea trifolia, a shrub which is considered native to western New England, but not to RI.
There was no evidence that this population had been planted. Is this shrub native to RI or was it introduced?  I like to think it is a native, but, whether native or naturalized, it’s a welcome newcomer to RI.

One-cone ClubmossLycopodium lagopus (Laes. ex Hartm.) G. Zins. ex Kuz.-Proch., One-cone Clubmoss. One-cone Clubmoss is primarily a northern plant ranging from Greenland south to Connecticut. Reported from ME, NH, VT, MA and CT and found in Exeter, RI growing in pine woods on August 11, 2006. For a discussion of L. lagopus, see Botanical Notes by A. Haines, #8 May 23, 2002. (See link at end of "Undiscovered Plants.")



Variegated HorsetailEquisetum variegatum (Schl. ex Web.) & Mohr ssp. variegatum, Variegated Horsetail
Recorded in all New England states except RI until discovered in West Greenwich on June 15, 2003 growing in moist sandy soil.






Early Blue VioletViola subsinuata Greene, Early Blue Violet
CT, MA and VT  Found in Charlestown, RI on November 10, 2002.  Grows in rich woods. For a discussion of V. subsinuata, see Botanical Notes by A. Haines, #8 May 23, 2002. (See link at end of "Undiscovered Plants.")



Threadleaf ArrowheadSagittaria filiformis J.G. Sm., Threadleaf Arrowhead. This is a confusing taxon. It is either a form of S. subulata or a distinct taxon by itself. S. filiformis grows in abundance in Warwick and Cranston, RI. Found in August 10, 2004. Occurs in rivers.  




Fall WitchgrassDigitaria cognata (J.A. Schult.) Pilger, Fall Witchgrass
Formerly called Leptoloma cognatum This is another plant which is listed for all New England states except RI. It is not included in Gould et al.  Gil George found this grass on Block Island. Also observed by the author in Warwick and West Greenwich in 2005. It grows in sandy habitats.




Rigid SedgeCarex conoidea, Field Sedge. When this article first appeared in Among RI Wildflowers, I  identified this plant incorrectly as Carex tetanica.  It is actually Carex conoidea, Field Sedge.  Field Sedge has been reported from Rhode Island in the past and it is not a rare plant in RI.  I apologize for my incorrect identification in the original article




Non-native Plants

Prostrate VervainVerbena bracteata, Lag. & Rodr. Prostrate Vervain. I observed this plant for the first time in East Greenwich in 1971 above the shoreline of Greenwich Cove.  Since then I have seen it at several other locations and it is now a member of RI’s flora.  It was probably never native to the state, but has become naturalized. This plant also occurs in East Providence, Warwick, a second site in East Greenwich and very likely at other locations in RI.


Blue Scorpion-grassMyosotis stricta Link ex Roemer & J.A. Schultes, Blue Scorpion-grass.  M. stricta is not a grass at all, but a member of the Forget-me-not or Borage family. It occurs at several sites in RI.  I first saw this plant in Rumford and since then I have seen it in Hopkinton, Cranston, and Providence. It probably occurs at other sites as well.



Hairy Bitter-cressCardamine hirsuta L., Hairy Bitter-cress, appears to be quite aggressive in RI.  My most recent sighting was in Narragansett adjacent to the cobble beach below the GSO. Other sightings were in Warwick, Providence, Cranston , East Providence near Watchemocket Cove, and Cumberland off Scott Rd. Surprisingly, Hairy bitter-cress is not on the IPANE list.



Wavy Bitter-cressCardamine flexuosa With., Wavy Bitter-cress grows in a marsh in Lincoln, RI.  Photo shows flexuous stem.







Narrow-leaved BittercressCardamine impatiens L., Narrow-leaved Bitter-cress, occurs in Exeter along Summit Rd. Narrow-leaved bitter-cress is listed as an invasive species by IPANE.






Japanese PearlwortAlong the banks of the Woonasquatucket River in Providence, the alien Japanese Pearlwort, Sagina japonica, grows abundantly. Unlike our native Birdseye pearlwort, S. japonica has large showy, white flowers.




Water CabbagePistia stratiotes L., Water Cabbage. I found Water Cabbage growing in a pond at the Round Top Fishing area in Burrilvile in 2005.  There were numerous plants, but since it is a tropical plant, it apparently did not survive RI’s winter. Water Cabbage is listed as an invasive by IPANE.


Scotch Cotton-thistleOnopordum acanthium L. ssp. acanthium, Scotch Cotton-thistle grows in a field in Warwick. Onopordum is also an invasive.




CeleryApium graveolens L.,  Celery.  In 2003 I found Wild Celery growing along the Seekonk River in East Providence.  In order to identify it I had to transplant one plant to a pot and grow it until it produced flowers. Richard Champlin confirmed the identification of this plant.




Readers who have observed any of the above species in RI are encouraged to send an email to us at


Link to Botanical Notes by A. Haines, #8 May 23, 2002.


Stout GoldenrodSolidago squarrosa

A reader sent us an email saying he knows of a single specimen of Solidago squarrosa growing in Warwick, RI.  He said it has been there since at least 1995.


I got the following e-mail from Anne B. Wagner of Portsmouth:

Cuckoo FlowerSeveral years ago I collected seed of Solidago squarrosa in southern Maine, propagated it and planted it in my garden. I may have shared seed with RIWPS Seedstarter group and I may have donated plants to RIWPS plant sale. It grows well in sandy, gravelly soil and in part shade, so is very useful in gardens with poor acid soils. Gil George and I inventoried the Norman Bird Sanctuary properties in 1998 and identified Cuckoo-flower growing there. It is especially prominent in the wetlands alongside Hanging Rock Road in Middletown.

In last month’s “Report on Finds of the 2008 Season” I wrote that the Leptochloa specimen was awaiting confirmation. I have now learned that my identification of Leptochloa fusca ssp. fascicularis has been confirmed.