Tilia americana

Tilia americana

The American Basswood (Tilia americana L.) is an arboreal species belonging to the Malvaceae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota Domain,
Kingdom Plantae,
Magnoliophyta Division,
Magnoliopsida class,
Subclass Dilleniidae,
Malvales Order,
Malvaceae family,
Subfamily Tilioideae,
Genus Tilia,
T. americana species.
The following terms are synonymous:
– Tilia alabamensis Ashe;
– Tilia americana f. ampelophylla V.Engl.;
– Tilia americana f. cyclophylla V.Engl.;
– Tilia americana f. dentata (G.Kirchn.) Rehder;
– Tilia americana f. divaricata V.Engl.;
– Tilia americana f. fastigiata (A.D.Slavin) Rehder;
– Tilia americana f. grandifolia V.Engl.;
– Tilia americana f. laxiflora (Michx.) V.Engl.;
– Tilia americana f. macrophylla (Fisch. ex Bayer) V.Engl.;
– Tilia americana f. megalodonta V.Engl.;
– Tilia americana f. microphylla Farw.;
– Tilia americana f. microptera V.Engl.;
– Tilia americana f. moltkei L.Späth;
– Tilia americana f. moltkei L.Späth ex Dippel;
– Tilia americana f. pedunculata V.Engl.;
– Tilia americana subsp. neglecta (Spach) Fosberg;
– Tilia americana var. americana;
– Tilia americana var. caroliniana (Mill.) Castigl.;
– Tilia americana var. densiflora V.Engl.;
– Tilia americana var. missisippiensis (Bosc ex Spach) Schelle;
– Tilia americana var. neglecta (Spach) Fosberg;
– Tilia americana var. pubescens Loudon;
– Tilia americana var. scabra Farw.;
– Tilia americana var. vestita V.Engl.;
– Tilia americana var. walteri Alph.Wood;
– Tilia apposita Ashe;
– Tilia ashei Bush;
– Tilia canadensis Michx.;
– Tilia caroliniana var. lata (Ashe) Ashe;
– Tilia caroliniana var. vagans V.Engl.;
– Tilia cocksii Sarg.;
– Tilia crenoserrata Sarg.;
– Tilia crenoserrata var. acuminata Ashe;
– Tilia excellens J.Wagner;
– Tilia floribunda A.Br. ex Döll, 1843;
– Tilia floridana var. alabamensis (Ashe) Ashe;
– Tilia georgiana var. crinita Sarg.;
– Tilia glabra Vent.;
– Tilia glabra f. fastigiata A.D.Slavin;
– Tilia glabra var. fastigiata Slavin;
– Tilia glabra var. neglecta Bush;
– Tilia grata Salisb.;
– Tilia heterophylla var. amphiloba Sarg.;
– Tilia heterophylla var. microdonta V.Engl.;
– Tilia heterophylla var. nivea Sarg.;
– Tilia heterophylla var. tenera (Ashe) Ashe;
– Tilia hollandica Du Roi;
– Tilia hollandica Du Roi ex Steud.;
– Tilia incisodentata K.Koch;
– Tilia lata Ashe;
– Tilia latifolia Salisb.;
– Tilia laxiflora Michx.;
– Tilia leptophylla Hort.Berol.;
– Tilia leptophylla Hort.Berol. ex Bayer;
– Tilia leucocarpa f. attenuata Ashe;
– Tilia leucocarpa f. attenuata Ashe ex Bush;
– Tilia leucocarpa var. cocksii (Sarg.) Ashe;
– Tilia leucocarpa var. glaucescens (Sarg.) Sudw.;
– Tilia littoralis var. discolor Sarg.;
– Tilia longifolia Raf.;
– Tilia longifolia var. dentata G.Kirchn.;
– Tilia ludovicia Bosc;
– Tilia ludovicia Bosc ex Koehne;
– Tilia mexicana Schltdl.;
– Tilia mexicana f. pringlei V.Engl.;
– Tilia mexicana var. houghii V.Engl.;
– Tilia mississippiensis Bosc;
– Tilia mississippiensis Bosc ex Spach;
– Tilia moltkei (L.Späth ex Dippel) C.K.Schneid. ex Elwes, 1913;
– Tilia multiflora hort.;
– Tilia multiflora hort. ex Vent.;
– Tilia neglecta Spach;
– Tilia nigra Borkh.;
– Tilia nigra var. laxiflora (Michx.) Spach;
– Tilia nigra var. macrophylla Fisch.;
– Tilia nigra var. macrophylla Fisch. ex Bayer;
– Tilia nigra var. vestita A.Braun;
– Tilia nuda Sarg.;
– Tilia nuda var. glaucescens Sarg.;
– Tilia pallida Salisb.;
– Tilia palmeri Bush;
– Tilia palmeri Bush ex F.C.Gates;
– Tilia patzcuaroana Bush;
– Tilia phanera Sarg.;
– Tilia phanera var. scabrida Sarg.;
– Tilia praecox A.Br. ex Döll, 1843;
– Tilia pringlei Rose;
– Tilia pubescens f. glabrata V.Engl.;
– Tilia pubescens f. gymnophila V.Engl.;
– Tilia pubescens f. heteromorpha V.Engl.;
– Tilia pubescens f. truncata (Spach) V.Engl.;
– Tilia pubescens var. aitonii V.Engl.;
– Tilia pubescens var. ventenatii V.Engl.;
– Tilia relicta Laughlin;
– Tilia stellata Hartig;
– Tilia stenopetala Raf.;
– Tilia tenera Ashe;
– Tilia texana Sarg.;
– Tilia texana var. grosseserrata Sarg.;
– Tilia truncata Spach;
– Tilia velutina Mack.;
– Tilia velutina Mack. ex V.Engl.;
– Tilia venulosa Sarg.;
– Tilia venulosa var. multinervis Sarg.;
– Tilia viridis nothosubsp. moltkei (Dippel) Xifreda, 1998.
Within this species, the following varieties and forms are recognized:
– Tilia americana var. caroliniana (Mill.) A.E.Murray;
– Tilia americana var. heterophylla (Vent.) Loudon;
– Tilia americana var. mexicana (Schltdl.) Hardin;
– Tilia americana var. pubescens Dippel, 1893;
– Tilia americana f. americana;
– Tilia americana f. rosenthalii (Dippel) V.Engl..

Etymology –
The term Tilia comes from tilia, the Latin name of the lime tree in Virgil and Columella.
The specific American epithet refers to the origins of the Americas (Northern, Central and Southern): of the species.

Geographic Distribution and Habitat –
Tilia americana is a tree native to eastern North America, present from south-east Manitoba to east to New Brunswick, from south-west to north-east of Oklahoma, to south-east of South Carolina and west along the Niobrara River to Cherry County, Nebraska. It is the only representative of its kind in the Western Hemisphere, assuming that T. caroliniana is treated as a subspecies or local ecotype of T. americana.
This plant was introduced in Europe as an ornamental plant and today it is quite widespread in parks, gardens and road trees, even throughout Italy.
Its natural habitat is that of rich, often humid soils of woods and plains, where it often forms pure populations. In areas where it has been imported it sometimes escapes cultivation and also appears in a sub spontaneous state.

Description –
The American Basswood is a medium-large deciduous tree that reaches a height of 18 to 37 m and, exceptionally, 39 m.
The trunk has a diameter of 1–1.5 m at maturity. This plant has a life expectancy of around 200 years, with flowering and seed production generally occurring between 15 and 100 years, although occasionally seed production can begin as early as eight years.
It has a domed crown and the branches expand and are often pendulous. The bark is gray to light brown in color, with narrow, well-defined cracks. The roots are large, deep and widespread. The twigs are smooth, reddish-green, turning light gray in the second year, eventually dark brown or brownish gray, marked by dark wart-like growths. The winter shoots are robust, ovate-acute, smooth, deep red, with two visible bud scales.
The leaves are simple, alternately arranged, ovate to cordate, asymmetrical, unequal at the base (the side closest to the branch the largest), 10-15 cm long but can reach up to 25 cm with a long and slender petiole , a coarsely serrated margin and a sharp apex. The autumn color ranges from yellow-green to yellow. Both twigs and leaves contain mucilaginous sap.
The flowers are small, fragrant, yellowish-white, 10–14 mm in diameter, arranged in hanging, selvedge clusters of 6–20 with a whitish-green leaf-like bract attached half its length to the base of the top. They are perfect, regular, with five sepals and petals, numerous stamens and a five-celled upper ovary. The leaves emerge in mid-spring, but the flowers require a day duration of about 14 hours and 30 minutes to form, so the T. americana range is limited north of the 35th parallel.
The flowering time varies by several weeks depending on the latitude but runs from May to July.
Leaf fall in autumn occurs between early and late October depending on latitude. The flowers are fragrant and pollinated by insects.
The fruit is a small, globose, fluffy, hard and dry cream colored nut with a diameter of 8-10 mm.

Cultivation –
Tilia americana is a tree that for cultivation prefers soils with a good content of organic matter, clayey, from alkaline to neutral but succeeds on slightly acid soils.
It does not like exposed positions and prefers sunny or even half-shaded positions.
It is a fast-growing and moderately long-lived tree, starting to produce seed at the age of around 15 and continuing for at least another 85 years.
Trees respond well to coppice, generating many root suckers.
This plant can be propagated by cuttings and grafting as well as by seed. Propagated plants grow rapidly in rich soil, but are susceptible to many pests.
Overall it is, however, one of the most difficult native North American trees to propagate from seeds, as it not only has a low viability rate (about 30% of all seeds are viable), but quickly develops an extremely hard seed coat that it can delay germination for up to two years. If planting them, it is recommended that you harvest the seeds in early fall and sow them before they dry out and form a coating. This will then allow germination to take place immediately. Overall, seeds are not an important part of the tree’s reproductive strategy which instead spreads primarily by coppicing. All young linden woods yield very easily and even old trees often sprout from the stump when cut.
This tree is recommended as an ornamental when a mass of foliage or deep shade is desired; no tree native to the same area surpasses it in this sense. It is often planted on the windward side of orchards as a protection for young, delicate trees.

Customs and Traditions –
American Basswood is a dominant plant in the most common forest association in western Wisconsin and central Minnesota, but is found as far east as New England and southern Quebec in locations that have relatively high pH mesic soil. It also has a minor presence in many other types of forest cover.
It is a plant that is used in both food and medicine.
The young leaves are eaten both raw and cooked; they have a delicate flavor and a tender but mucilaginous consistency, they are very pleasant in salads or they can be cooked like vegetables.
The sap obtained from the bark is used as a refreshing drink and can also be concentrated into a syrup and used as a sweetener.
Raw flowers can be added to salads or used as a tea substitute and are sweet and fragrant.
An excellent chocolate substitute is obtained from a paste of ground fruits and flowers.
The flowers, leaves, wood and charcoal (obtained from wood) are used for medicinal purposes. The active ingredients in lime blossom include flavonoids (which act as antioxidants), volatile oils, and mucilaginous constituents (which soothe and reduce inflammation). The plant also contains tannins which can act as astringents.
Linden flowers are used against colds, coughs, fever, infections, inflammation, hypertension, headaches (especially migraines), as a diuretic, antispasmodic (reduces the spasm of smooth muscles along the digestive tract) and sedative. The flowers were added to baths to quell hysteria and used as a tea to relieve anxiety-related indigestion, irregular heartbeat and vomiting. The leaves are used to promote sweating and to reduce fever. Wood is used for liver and gallbladder disorders and for cellulite (inflammation of the skin and surrounding soft tissues). Wood burned and reduced to charcoal is ingested to treat intestinal disorders and used topically to treat edema or infections, such as cellulitis or ulcers of the lower legs.
Several animal studies have shown that T. americana extract increases sleep time by 50 minutes (similar to the effects of diazepam) and decreases movement, indicating sedative effects. It is claimed that its mechanism of action is due to the flavonoid quercetin, as it inhibits the release of histamine.
As for other uses, the wood is light brown, sometimes almost white or slightly tinged with red; light, soft with fine and dense grain; free of knots but does not break easily. It is low strength and has a poor steam bending rating. It can take stains and polish without difficulty and planes, glues, screws and nails well.
It is generally sold under the name lime tree, but is sometimes confused with Liriodendron tulipifera and therefore called white wood, and is widely used in the manufacture of wooden items, wagon crates and furniture. It has a density of 0.4525 (relative to water). Wood is considered odorless. This makes it valuable in the manufacture of wooden objects, cheap furniture and bodywork; it is also particularly suitable for wood carving. The inner bark is very tough and fibrous, used in the past to make ropes.
It is a common wood for use in the production of solid-body electric guitars, where it is considered an analogue of aspen and poplar, because it is light, strong and resonant, although it is usually used for guitars that will be painted with a dull color, because its lack of noticeable grain makes it an unattractive candidate for the clear finish.
From an ecological point of view, its flowers provide abundant nectar for insects. The seeds are eaten by squirrels, mice and chipmunks. Rabbits and voles eat the bark, sometimes encircling young trees. The leaves serve as food for the caterpillars of various moths.
This plant is particularly susceptible to adult Japanese beetles (an invasive species in North America) that feed on its leaves. Pholiota squarrosoides fungus is known to cause tree trunks to decompose.

Preparation Method –
Tilia americana is a tree that has various uses in both the food and medicinal fields.
The leaves are eaten young, raw or cooked as vegetables.
Refreshing drinks are prepared from the sap which can be concentrated in syrups.
The flowers are eaten raw and added to salads or used as a tea substitute. They taste sweet and are fragrant.
From a paste of ground fruits and flowers, an excellent chocolate substitute is obtained which, however, cannot be commercialized because the paste decomposes easily.
In the medical field, a tea obtained from the inner bark is used to soothe and soften the skin and is taken internally in the treatment of lung ailments, dysentery, heartburn and stomach weakness.
The bark is taken internally, as an infusion, to encourage urination while a decoction of the bark, mixed with corn flour, was used as a poultice.
Tea made from fresh or dried flowers is antispasmodic, diaphoretic and sedative and is used in the treatment of hypertension, hardening of the arteries, digestive disorders associated with anxiety, febrile colds, respiratory phlegm, migraines, etc.
Linden blossoms are said to develop narcotic properties as they age and therefore should only be harvested when freshly opened.
An infusion of the leaves was used as an eye drop.
A poultice of the leaves has been used in the treatment of burns and scalds, broken bones and swollen areas.
A tea or tincture made from leaves, flowers, and buds has traditionally been used for nervous headaches, restlessness, and painful digestion.
A decoction of the roots and bark has been taken in the treatment of internal bleeding or as a vermifuge to rid the body of worms.

Guido Bissanti

Sources
– Acta Plantarum – Flora of the Italian Regions.
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (ed.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora of Italy, Edagricole, Bologna.
– Treben M., 2000. Health from the Lord’s Pharmacy, Advice and experiences with medicinal herbs, Ennsthaler Editore.
Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/193391770/original.jpeg

Warning: Pharmaceutical applications and alimurgical uses are indicated for informational purposes only, they do not represent in any way a medical prescription; therefore no responsibility is taken for their use for curative, aesthetic or food purposes.