Willows of Massachusetts

Checklist
Initially, this list was based on the 'County Checklist' by B.A. Sorrie and P. Somers (1999) and publications of G. Argus (1986, 1997, 2005, 2007, 2010), though only some of the hybrids have been included. Classification of willows on the section level follows G. Argus. Names of sections used by A. Skvortsov (1999) are also shown when different. Species marked by the asterisk (*) have been erroneously reported for Massachusetts; some occur only in adjacent states. Most county records still need to be verified.

Subgenus Salix

Section Humboldtianae

* Salix amygdaloides   Andersson
Not found in Massachusetts.
It has been reported for New Hampshire, Vermont and Massachusetts, but probably all records for New England are misidentifications (see Argus 2007, 2010)
Images from other sites: [1]
Salix nigra   Marshall
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA DU
Among the native willows, it is one of the most common and readily recognizable species.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31]

Section Triandrae

* Salix triandra   L.
Not found in Massachusetts. - Introduced
Reported as introduced and naturalized in Maine (Penobscot River, Orono)

Section Salicaster = Pentandrae

Salix serissima   (L. H. Bailey) Fernald
MA counties: BE - Watch List
Links: [PDF]
* Salix pentandra   L.
MA counties: - Records are based on misidentification.
S. pentandra is a boreal species native for Europe and West Siberia. It is considered to be introduced to about half of the states and reported from most of the counties in Massachusetts (BE HD WO MI ES NO BA DU NA). However, I treat all records for this willow from North America as collections from cultivated plants or misidentifications, mostly of S. x meyeriana. — A. Zinovjev (10 Jul 2010 — 30 Dec 2010)
See more: [1] [2] (herbarium material examined: formerly identified as S. pentandra)
Photos of S. pentandra from N Europe (Finland): [1], [2], [3], [4], [5], [6], [7]
Salix x meyeriana   Rostk. ex Willd. ( = S. pentandra x S. euxina  )
MA counties: BE FR? HS(cultivated) HD? WO MI ES SU(?cultivated) NO PL(cultivated) BA DU NA?
Most records of S. pentandra from North America belong to these hybrids, though it is not always possible to reliably distinguish hybrids from parent species in herbarium material. Cultivated in Arnold Arboretum under the name S. pentandra. —  A. Zinovjev (10 Jul  — 30 Dec 2010)
See more: [1] [2] (herbarium material, most definitely identified as S. x meyeriana)
Photos of S. pentandra x S. euxina outside North America: [1]
Salix lucida   Muhlenberg
MA counties: BE FR HS HD WO MI ES SU NO PL BA DU
According to herbarium material, it used to be broadly distributed in Massachusetts, though so far we have never found a single one around Boston.
See more: [1]
Images from other sites: [1]
Salix x jesupii   Fernald ( = S. alba L. x S. lucida Muhl., not S. x ehrhartiana (S. alba x S. pentandra) auct.  )
MA counties: BE
In herbaria, specimens of S. x jesupii (Salix alba x S. lucida) can be misidentified as S. alba, or S. x fragilis. Resembles S. x erhartiana but young leaves with reddish hairs. Reported from Massachusetts by Argus (2010): according to the samples from the Harvard University Herbaria, it has been found only in Berkshire Co.

Section Salix

Salix x fragilis   L.
MA counties: BE FR HS HD WO MI ES SU NO BR NA - Introduced
A willow originating from Asia Minor and Transcaucasia was introduced to Europe during the Middle Ages. In Western Europe it then started hybridizing with closely related S. alba on a grand scale, so that S. alba as a result mostly lost its characteristic features (see the translation of Skvortsov's 1973 article at this site). As the name "Salix fragilis" (crack willow) has been constantly misapplied to the widespread hybrids of the Asiatic willow with S. alba, NCVP (Nomenclature Committee for Vascular Plants) recently voted for the name "fragilis" to be retained for these hybrids. In other words, hybrids formerly known as S. alba x S. fragilis should now be named S. x fragilis L. (= S. decipiens Hoffm., S. x rubens Schrank). Thus there is no name "left" for the parent willow from Asia Minor. That species originating from Turkey and Georgia has been newly described as S. euxina Belyaeva (2009, Taxon 58: 1345).
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
Salix euxina   Belyaeva ( = Salix fragilis auct. in part., non L. )
MA counties: NO - Introduced
Salix euxina Belyaeva 2009 (= S. fragilis auct., partim; S. decipiens auct.) is native to a comparatively small area in Asia Minor and Transcaucasia (see S. x fragilis). For characters distinguishing this willow from S. alba and hybrids, see the article by Belyaeva (2009, Taxon 58: 1345) and translation of Skvortsov's article (1973), where this species was named S. fragilis.
Images from Massachusetts Plant Gallery: [1] [2] [3]
Salix alba   L.
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA NA - Introduced
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]

Section Subalbae

* Salix babylonica   L. ( = Salix matsudana Koidz. )
MA counties: - Records are based on misidentification.
For centuries this willow, known as Babylon weeping willow, has been favored for cultivation around the world. The name is misleading, since the species actually originates from arid and semi-arid regions of China. A weeping clone of Salix babylonica L. was introduced to Europe from the Near East, supposedly in 17th century. From Europe it was exported to North America. Though it is naturalized in the southeastern US, all New England records are based on cultivated specimens or hybrids: S. x pendulina (a hybrid of S. babylonica with S. euxina or S. x fragilis) and S. x sepulcralis (S. babylonica x S. alba). According to Argus (2007), pure S. babylonica is not found anywhere north of Maryland and West Virginia. Therefore, S. babylonica is to be excluded from New England checklists. However, it may still be cultivated in Massachusetts. Outside the Arnold Arboretum, we have found its non-weeping cultivar known as Salix matsudana var. tortuosa (corkscrew willow) grown in Weymouth see: [1] [2] [3].
Salix babylonica   hybrids ( predominantly S. x sepulcralis  )
MA counties: FR HD WO MI ES SU NO BA NA - Introduced
All, or nearly all records of S. babylonica from New England are hybrids of S. babylonica with willows from the section Salix.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6]

Subgenus Longifoliae

Section Longifoliae

Salix interior   Rowlee
MA counties: FR HS HD (native) MI (introduced) - Special Concern

Subgenus Chamaetia

Section Myrtilloides

Salix pedicellaris   Pursh
MA counties: BE FR WO MI ES SU NO PL - Watch List
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14]

Subgenus Vetrix

Section Hastatae

* Salix cordata   Michaux
Not found in Massachusetts.
Not found in New England. The historic record from Barnstable was obviously based on a misidentification. Mostly distributed within the US, around the Great Lakes, with isolated locations in Canada.
Images from other sites: [1]
* Salix myricoides   Muhlenberg
Not found in Massachusetts.
The species is known from Maine (where it is considered Endangered). Must be erroneously listed for Massachusetts in Magee and Ahles (1999). Not shown for Massachusetts in the Flora of North America (Argus 2010).
Images from other sites: [1]

Section Cordatae = Hastatae (in part)

Salix eriocephala   Michaux ( = S. cordata Muhlenberg, non Michaux; S. rigida Muhlenberg )
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA NA
One of the most common native willows in eastern MA and around Boston.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40]

Section Cinerella = Vetrix (in part)

* Salix aurita   L.
Not found in Massachusetts.
A European willow. Argus (2005, 2007) shows this species for Pennsylvania and Massachusetts. A possibility of its naturalization in North America is questionable.
Images from other sites: [1]
* Salix caprea   L.
Not found in Massachusetts.
A Eurasian willow. This name is frequently used in American horticultural context for "pussy willow", which can hardly be true, since S. caprea, as opposed to most of related willows, is very difficult to propagate. Records of S. caprea may be attributed to S. cinerea L., S. atrocinerea Brotero, S. aegyptiaca L. There is a noteworthy remark by A. Skvortsov (1999: 178) about S. aegyptiaca: It is favored for cultivation, since it is easily propagated from cuttings, unlike S. caprea.
Images from other sites: [1] [2]
Salix cinerea   L.
MA counties: SU ES MI NO BA DU NA (the latter two not verified) - Introduced
We treat S. cinerea and S. atrocinerea as different species rather than subspecies. In eastern Massachusetts S. cinerea appears to be much more rare than S. atrocinerea.
See more on distinguishing between the two closely related species [1].
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Salix atrocinerea   Brotero ( = Salix cinerea ssp. oleifolia (Smith) Macreight )
MA counties: HS HD WO MI ES SU NO BR PL BA DU NA - Introduced - Invasive
Native to Sub-Atlantic Europe. Highly invasive, though overlooked for a long time having been confused with native willows. Has been frequently treated as a subspecies of Eurasian S. cinerea.
See more: [1] [2] [3] [4] [5] [6] [7]
Other links: [1], [PDF or DOC] (entries dated October 2005)
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39]
Salix discolor   Muhlenberg
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA DU NA
One of the most common native willows.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36]
Salix humilis   Marshall ( = Salix humilis var. humilis Marshall )
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA DU NA
It has become rather scarce in eastern counties; appears to be still frequent in central MA.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36] [37] [38] [39] [40] [41] [42]
Salix occidentalis   Walter ( = S. tristis Aiton; S. humilis var. tristis (Aiton) Griggs; S. humilis var. microphylla (Andersson) Fernald )
MA counties: FR HS HD WO MI ES SU NO BR PL BA DU NA
Some authors, including G. Argus (2010), consider this tiny willow to be a variety of S. humilis. We follow Skvortsov's opinion that these are two distinct species.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27]

Section Fulvae = Vetrix subsect. Substriatae

Salix bebbiana   Sargent
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA DU NA
The species has disappeared from eastern Massachusetts; has become infrequent in Worcester Co.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24]

Section Candidae

Salix candida   Flugge ex Willdenow
MA counties: BE FR ES - Watch List
Images from other sites: [1]

Section Viminella = Vimen

Salix viminalis   L.
MA counties: FR MI ES SU NO NA - Introduced
An Eurasian species introduced to North America. We have not seen it anywhere in a natural setting.
Images from other sites: [1]

Section Canae

Salix elaeagnos   Scopoli
MA counties: BA - Introduced
This species has been introduced from Central Europe. The only specimen in Massachusetts we saw so far is a cultivar 'Angustifolia' on the Arnold Arboretum grounds. Historically it is known from a single location on Cape Cod.
Images from other sites: [1]

Section Geyerianae

Salix petiolaris   Smith
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA NA
Not infrequent around Boston, particularly in the floodplains of the Charles and Neponset.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33]

Section Griseae

Salix sericea   Marshall
MA counties: BE FR HS HD WO MI ES SU NO BR PL BA NA
Infrequent around Boston, becoming more common in Worcester Co.
Images from Massachusetts Plant Gallery: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]

Section Daphnella

Salix daphnoides   Villars
MA counties: - Introduced
A European species. According to Argus (2010) introduced in Massachusetts and Minnesota, and in four provinces in Canada.
Images from other sites: [1]

Section Helix

Salix purpurea   L.
MA counties: BE FR HS HD WO MI ES SU NO PL BA DU NA - Introduced
A European species that is frequently cultivated. We have not yet seen it naturalized.

References

Argus, G. W. 1986. The genus Salix (Salicaceae) in the Southeastern United States. Systematic Botany Monographs. Vol 9. 170 pp.
Argus, G. W. 1997. Infrageneric classification of Salix (Salicaceae) in the New World. Systematic Botany Monographs. Vol. 52. 121 pp.
Argus, G. W. 2004
Argus, G. W. 2005. Guide to the identification of the Genus Salix (Willow) in New England and New York. Unpublished manuscript (online version not available anymore).
Argus, G. W. 2007. Salix L. (Salicaceae) distribution maps and a synopsis of their classification in North America, north of Mexico. Harvard Papers in Botany 12: 335-368. Online version: http://aknhp.uaa.alaska.edu/willow/pdfs/Argus_2007_Synopsis_Maps.pdf (accessed 5 April 2009).
Argus, G. W. 2010. Salix — In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 12+ vols. New York and Oxford. Vol. 7:
Belyaeva, I. 2009. Nomenclature of Salix fragilis L. and a new species, S. euxina (Salicaceae) — Taxon 58: 1344-1348.
Fernald, M. L. 1950. Gray's Manual of Botany, ed. 8. New York.
Gleason, H. A. and A. Cronquist. 1991. Manual of vascular plants of Northeastern United States and adjacent Canada. N. Y. Botanical Garden.
Haines, A. and T. Vining. 1998. Flora of Maine. Bar Harbor, Maine: V. F. Thomas Co. [Salix pp. 476-491.]
Magee, D.W. and Ahles, H. E. 1999 Flora of the Northeast : A Manual of the Vascular Flora of New England and Adjacent New York. 1264 pp.
Skvortsov, A.K. 1955. [The willows of Central European Russia and their identification during the wintertime]. — Byull. MOIP, Otd. biol. 60 (3): 115-127. In Russian. English translation: http://salicicola.com/translations/Skvortsov1955.html
Skvortsov, A.K. 1960. Salix pentandra and related species. — Trudy MOIP 3: 247-262. In Russian.
Skvortsov, A.K. 1973. [Present distribution and probable primary range of brittle willow (Salix fragilis L.)]. Problemy biogeotsenologii, geobotaniki i botanicheskoy geografii. Leningrad, Nauka, pp. 263-280. In Russian. English translation: www.salicicola.com/translations/Skv1973SF.html
Skvortsov, A.K. 1999. Willows of Russia and adjacent countries. Taxonomical and geographical revision. University of Joensuu, Faculty of Mathematics and Natural Sciences, Report Series #39. Joensuu. English translation. 307 pp. Online version: http://www.salicicola.com/announcements/skv/skvortsov.pdf
Skvortsov, A.K. 2007. Present distribution and probable primary range of brittle willow (Salix fragilis L.) Problemy biogeotsenologii, geobotaniki i botanicheskoy geografii. Leningrad, Nauka, pp. 263-280. English translation: www.salicicola.com
Sorrie, B.A. and Somers, P. 1999. The vascular plants of Massachusetts: A county checklist. MA Division of Fisheries and Wildlife. Natural Heritage and Endangered Species Program. Westborough, MA. 188 pp.
1 Feb 2007 — 30 Dec 2010 (A. Zinovjev, I. Kadis) List of Salicicola Plant Gallery images generated: Thu Dec 30 05:43:08 PST 2010
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