Celtis

For the German Renaissance scholar, see Conrad Celtes. For the town, see Celtis, Missouri. For the tractor by CLAAS, see Claas Celtis

Hackberry (Celtis) is a genus of about 60-70 species of deciduous trees widespread in warm temperate regions of the Northern Hemisphere, in southern Europe, southern and eastern Asia, and southern and central North America, and south to central Africa. The genus is present in the fossil record at least since the Miocene of Europe.

Previously included either in the elm family (Ulmaceae) or a separate family Celtidaceae, they are placed in the hemp family (Cannabaceae) in the APG II system.

Description

They are generally medium-sized trees, reaching 10-25 m tall, rarely up to 40 m tall. The leaves are alternate, simple, 3-15 cm long, ovate-acuminate, and evenly serrated margins.

Small monoecious flowers appear in early spring while the leaves are still developing. Male flowers are longer and fuzzy. Female flowers are greenish and more rounded.

The fruit is a small drupe 6-10 mm diameter, edible in many species, with a dryish but sweet, sugary consistency, reminiscent of a date.

Uses and ecology

Several species are grown as ornamental trees, valued for their drought tolerance. They possess the most bending tolerance of all species of wood. They are a regular feature of arboretums and botanical gardens, particularly in North America. Especially Chinese Hackberry (C. sinensis) is suited for bonsai culture, while a magnificent Pseudo-hackberry (C. japonica) in Daegu-myeon is one of the natural monuments of South Korea. Some, including Common Hackberry (C. occidentalis) and C. brasiliensis, are honey plants and pollen source for honeybees of lesser importance.

The berries, as mentioned above, are often eaten locally. The Korean tea gamro cha (감로차, 甘露茶) contains leaves of C. sinensis.

Celtis species are used as foodplants by the caterpillars of certain Lepidoptera. These include mainly brush-footed butterflies, most importantly the distinct genus Libythea (beak butterflies) and some Apaturinae (emperor butterflies):

• Acytolepis puspa (Common Hedge Blue) – recorded on Chinese Hackberry (C. sinensis)
• Automeris io (Io Moth) – recorded on Southern Hackberry (C. laevigata)
• Asterocampa celtis (Hackberry Butterfly, Hackberry Emperor)
• A putative new taxon of the Two-barred Flasher (Astraptes fulgerator) cryptic species complex, provisionally called "CELT", has hitherto only been found on Celtis iguanaea.
• Libythea celtis (European Beak)
• Libythea labdaca (African Beak)
• Libythea lepita (Common Beak)
• Libythea myrrha (Club Beak) – recorded on C. tetranda
• Nymphalis xanthomelas (Scarce Tortoiseshell) – recorded on European Hackberry (C. australis)
• Sasakia charonda (Great Purple Emperor) – recorded on Japanese Hackberry (C. jessoensis) and Pseudo-hackberry (C. japonica)

The plant pathogenic basidiomycete fungus Perenniporia celtis was first described from a Celtis hostplant. Some species of Celtis are threatened by habitat destruction.

Selected species

• Celtis aetnensis
• Celtis africana Burm.f. – White Stinkwood
• Celtis australis – European Hackberry, European Nettle Tree, Lote tree
• Celtis balansae
• Celtis brasiliensis Planch.
• Celtis bungeana – Bunge's Hackberry
• Celtis caucasica – Caucasian Hackberry
• Celtis cinnamonea
• Celtis durandii Engl. (= C. gomphophylla Bak.)
• Celtis ehrenbergiana
• Celtis glabrata
• Celtis hypoleuca
• Celtis iguanaea (Jacq.) Planch.
• Celtis integrifolia – African Hackberry
• Celtis japonica – Pseudo-hackberry, Nakai or Paeng-na-mu (Korea) - sometimes considered a variety of C. sinensis
• Celtis jessoensis – Japanese Hackberry
• Celtis koraiensis – Korean Hackberry
• Celtis labilis – Hubei Hackberry
• Celtis laevigata – Southern Hackberry, Sugar Hackberry, (Southern/Texas) Sugarberry
• Celtis lindheimeri
• Celtis luzonica
• Celtis mildbraedii Engl.
• Celtis occidentalis – Common Hackberry, Northern Hackberry, False Elm
• Celtis pallida – Spiny Hackberry, granjeno (Spanish)
• Celtis paniculata
• Celtis reticulata – Net-leaved Hackberry
• Celtis sinensis – Chinese Hackberry
• Celtis tala – Tala
• Celtis tenuifolia – Dwarf Hackberry
• Celtis tetranda Roxb.
• Celtis tournefortii – Oriental Hackberry
• Celtis trinervia

See also

• Lotophagi
• William N. Barron

Footnotes

References

• (2006): Problems with DNA barcodes for species delimitation: ‘ten species’ of Astraptes fulgerator reassessed (Lepidoptera: Hesperiidae). Systematics and Biodiversity 4(2): 127–132. PDF fulltext
• (1900): Our Native Trees and How to Identify Them. Charles Scriber's Sons, New York.
• (2004): Ten species in one: DNA barcoding reveals cryptic species in the semitropical skipper butterfly Astraptes fulgerator. PNAS 101(41): 14812-14817. PDF fulltext Supporting Appendices