Common Names in English:
deciduous, monoecious. Stipules present, free
, often deciduous, rarely persistent
. Leaves alternate, simple
, usually doubly serrate, rarely simply serrate, lobulate
, or entire; veins pinnate. Flowers unisexual
. Male inflorescence precocious
, pendulous, with numerous
overlapping bracts; each bract usually subtending
a small dichasium with 1-3 male flowers; stamens as many as and opposite sepals or, if sepals obsolete
, then stamens of inflorescence to 20; filaments
very short, connate
or nearly so; anthers
2-loculed, thecae connate or separate, opening by longitudinal
slits. Female inflorescence pendulous or erect
, with numerous overlapping bracts; each bract subtending a small dichasium with 2 or 3 flowers; calyx with 1-6 scalelike lobes
, or obsolete; petals absent; ovary inferior, 2-loculed; styles 2, free; ovules 2, or 1 by abortion
, pendulous from near apex of each locule. Fruit a nut or nutlet
or not. Seed 1, with straight embryo and flat or thickened cotyledons, without endosperm.
Six genera and 150-200 species: mainly in Asia, Europe, and North and South America; six genera (one endemic) and 89 species (56 endemic) in China.
Because of evolutionary divergence within the Betulaceae, the family has often been divided into tribes (i.e. , Betuleae, Carpineae, and Coryleae) or more recently into subfamilies (J. J. Furlow, J. Arnold Arbor . 71: 1-67. 1990) .
, to 35 m
usually several, branching excurrent to deliquescent. Bark
of trunks and branches light gray to dark brown, thin, smooth
, close; lenticels
often present, pale
, sometimes horizontally expanded. Wood
nearly white, turning reddish upon exposure to air
, moderately light and soft, texture
fine. Branches, branchlets
, and twigs
nearly 2-ranked to diffuse
; young twigs uniform or ( Alnus subg. Alnobetula ) differentiated into long and short shoots
. Winter buds
(nearly sessile in Alnus subg. Alnobetula ), narrowly to broadly ovoid
, apex acute to rounded
, or ( Alnus subg. Alnobetula ) several, imbricate, smooth, or ( Alnus subg. Clethropsis ) sometimes none. Leaves borne on long or short shoots, 3-ranked to nearly 2-ranked. Leaf blade
, thin to leathery, base
variable, cuneate to rounded, margins
doubly serrate, serrate, serrulate
, or nearly entire, apex variable, acute to obtuse
or acuminate to rounded; surfaces glabrous
, abaxially sometimes resinous-glandular. Inflorescences: staminate
, in racemose clusters
or ( Alnus subg. Clethropsis ) solitary, formed ( Alnus subg. Alnus and Clethropsis ) during previous growing season
and exposed or enclosed in buds during winter, or ( Alnus subg. Clethropsis ) formed and expanding during same growing season, expanding before or with leaves; pistillate
to staminate catkins, solitary or in relatively small racemose clusters, erect
to nearly pendulous, ovoid to ellipsoid, firm; scales and flowers crowded, developing and maturing at same time as staminate catkins. Staminate flowers
in catkins, 3 per scale; stamens (3--) 4(--6) ; anthers
undivided. Pistillate flowers usually 2 per scale. Infructescences
erect or pendulous; scales persistent long after release
of fruits, with 5 lobes
, greatly thickened, woody. Fruits tiny samaras, lateral wings 2, leathery or membranaceous
, reduced or essentially absent in some species. x
Species ca. 25 (8 sp: forested temperate and boreal Northern Hemisphere; North America; Asia.
Alders resemble birches but are easily distinguished from them by the infructescences, which consist of persistent , 5-lobed, woody scales (versus deciduous, 3-lobed, thin scales). Except in members of Alnus subg. Alnobetula Petermann (which have nearly sessile buds with several imbricate scales), alders are also distinctive in their stipitate buds bearing two stipular scales. The fruits, borne two to a scale, are laterally winged , although the wings are sometimes reduced or absent.
The genus is diverse , including several very distinct lines of specialization. The shrubby or arborescent Alnus subg. Alnus is characterized by winter buds with long stalks and two valvate scales, inflorescences borne in racemose clusters, and development of both pistillate and staminate inflorescences during the growing season prior to anthesis , with these fully exposed during winter. It includes the common A. rubra, A. incana, A. oblongifolia, and A. serrulata. Alnus subg. Alnobetula (represented in North America by three subspecies of A. viridis ) consists of shrubby species of cold-climate regions. In this group, the buds are nearly sessile and covered by several imbricate scales. Both staminate and pistillate catkins are formed the season before anthesis, but only the staminate ones are exposed during winter. The predominantly Asian Alnus subg. Clethropsis (Spach) Regel is represented in America by a single species, A. maritima, a small tree or large shrub of stream banks, marshes, and the shores of shallow lakes . Members of this group are unique in that they bloom in autumn rather than spring . They also differ from other native species in Alnus in having essentially naked buds, leaves with semicraspedodromous venation (i.e. , with the secondary veins branching and anastomosing with each other near the margin before reaching the teeth), and solitary pistillate inflorescences borne in the axils of foliage leaves. All of the alders associate symbiotically with species of the actinomycete Frankia, leading to the formation of nodules on the roots of the plants and the fixation of atmospheric nitrogen.
Size: over 40' tall.
Typically found at an altitude of 0 to 1,287 meters (0 to 4,222 feet).
Culture: Space over 40' apart.
Soil: Minimum pH: 5.1 • Maximum pH: 7.8
Sunlight: Sun Exposure: Full Sun .
Temperature: Cold Hardiness: 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b. (map)
- Whittaker & Margulis,1978
- Haeckel, 1866
- Cavalier-Smith, 1981
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Kenrick & Crane, 1997
- Brongniart, 1843
- Takhtajan, 1967
- Superorder: Faganae () - (Engler, 1892) Takhtajan, 1997
- Subclass: Rosidae () - Takhtajan, 1967
- Class: Spermatopsida () - Brongniart, 1843
- Infraphylum: Radiatopses () - Kenrick & Crane, 1997
- Subphylum: Euphyllophytina ()
- Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
- Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
- Kingdom: Plantae () - Haeckel, 1866 - Plants
Alnus cordata Desf. • Alnus cordata var. rotundifolia (Bertol.) Dippel • Alnus cordifolia Ten. • Alnus cordifolia var. rotundifolia (Bertol.) Regel • Alnus macrocarpa Req. Ex Nyman • Alnus neapolitana Savi • Alnus nervosus Dippel • Alnus obcordata C. A. Mey. Ex Steud. • Alnus rotundifolia Bertol. • Betula cordata Loisel.
Members of the genus Alnus
ZipcodeZoo has pages for 28 species, subspecies, varieties, forms, and cultivars in this genus:
A. acuminata (Alder) · A. acuminata glabrata (Mexican Alder) · A. cordata (Italian Alder) · A. fallacina (Alder) · A. glutinosa (Black Alder) · A. glutinosa glutinosa (European Black Alder) · A. glutinosa 'Imperialis' (Black Alder) · A. glutinosa 'Pyramidalis' (Black Alder) · A. hirsuta (Manchurian Alder) · A. incana (Gray Alder) · A. incana incana (Speckled Alder) · A. incana rugosa (Gray Alder) · A. incana tenuifolia (Gray Alder) · A. japonica (Japanese Alder) · A. maritima (Seaside Alder) · A. nepalensis (Indian Alder) · A. nitida (West Himalayan Alder) · A. oblongifolia (Arizona Alder) · A. rhombifolia (Alder) · A. rubra (Oregon Alder) · A. rubra f. pinnatisecta (Oregon Alder) · A. serrulata (Alder) · A. viridis (Green Alder) · A. viridis crispa (Green Alder) · A. viridis fruticosa (Green Alder) · A. viridis sinuata (Green Alder) · A. viridis viridis (European Green Alder) · A. x fallacina (Alder)
- Search for Pictures: images.google.com
- Search for Scholarly Articles: Google Scholar
- Search using Scientific Name and Vernacular Names: All the Web | AltaVista Canada | AltaVista | Excite | Google | HotBot | Lycos
- Search using Specialized Databases: GenBank | Medline | Scirus | CISTI/CAL | Agricola Periodicals | Agricola Books
- A catalogue of the Cretaceous and Tertiary plants of North America by Frank Hall Knowlton. Washington: G.P.O., 1898. url .
- Annual report of the Board of Regents of the Smithsonian Institution. Washington: Smithsonian Institution, -1965. url p. 734, p. 734.
- Bulletin of miscellaneous information /Royal Botanic Gardens, Kew. 1916 London: H.M. Stationery Office, 1900-1941. url p. 283, p. 83.
- Bulletin of the American Museum of Natural History. New YorkAmerican Museum of Natural History1881- url p. 84.
- Contribution to the fossil flora of Florissant, Colorado. [n.p.]1898. url p. 166.
- Contributions to the fossil flora of the western territories. .. By Leo Lesquereux. Washington, Govt. Print. Off., 1874-1883. url p. 279.
- Curtis's botanical magazine. 142 1916 London; New York [etc.]: Academic Press [etc.] url .
- Cyclopedia of American horticulture, comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers and ornamental plants sold in the United by L. H. Bailey. .. assisted by William Miller. .. and many expert cultivators and botanists. London: The Macmillan company, 1909. url p. 47, p. 48.
- Danish fungi as represented in the herbarium of E. Rostrup / revised by J. Lind. Copenhagen: Gyldendalske boghandel, 1913. url p. 242.
- Forestry quarterly. Ithaca, N.Y. [etc.] url p. 465, p. 97.
- Hand-list of trees and shrubs, excluding Coniferae, grown in Arboretum. LondonPrinted for H.M. Stationery Off., by Darling1902 url p. 661.
- Journal of the New York Botanical Garden. 35 1934 Lancaster, Pa.: Published for the Garden by the New Era Printing Co., 1900- url p. 162, p. 223, p. 289.
- Landscape reclamation: a report on research into problems of reclaiming derelict land, by a research team of the University of Newcastle upon Tyne. GuildfordIPC Science and Technology Press1971- url p. 18.
- Lists of plant types for landscape planting; the materials of planting for ornament listed according to their various uses, by Stephen F. Hamblin. Cambridge, Harvard University Press, 1923. url , , p. 20, p. 23.
- Marcellia. New York [etc.]Pergamon Press [etc.] url p. 77.
- New illustrated encyclopedia of gardening, unabridged. Edited by T.H. Everett, with contributions from twenty horticulturists and authorities in the United States and Canada. New York, Greystone Press[1964-] url p. 80, p. 81.
- Nicholson, G. The illustrated dictionary of gardening: a practical and scientific encyclopædia of horticulture for gardeners and botanists /edited by George Nicholson; assisted by J.W.H. Trail. .. and J. Garrett. .. 9 1884 London: L.U. Gill, -88. url p. 451.
- Practical foresty; a popular handbook on the rearing and growth of trees for profit or ornament. LondonW. Rider[pref.1917] url p. 137.
- Proceedings of the United States National Museum. Washington: Smithsonian Institution Press, [etc.] url p. 264, p. 290, p. 664.
- Recent advances in cytology, by C. D. Darlington. With a foreword by J. B. S. Haldane. With 16 plates, 160 text-figures and 81 tables. Philadelphia, P. Blakiston's son & co., inc., 1937. url p. 216.
- Report of the United States Geological Survey of the territories. F.V. Hayden, United States geologist in charge. .. [Final reports or monographs. vol. I]-III, V-XIII. Washington, Govt. Print. Off., 1873-90. url .
- Reports of the Director. .. / Experimental Farms. Ottawa: Experimental Farms, 1888-1916. url p. 306.
- The Entomologist's record and journal of variation. s.l., s.n. url p. 288, p. 307.
- The Farmer's magazine. [London: Rogerson and Tuxford, 1834-1881. url p. 325.
- The Garden: an illustrated weekly journal of gardening in all its branches. London: [s.n., url , , p. 178, p. 221, p. 42, p. 434, p. 500, p. 580.
- The Gardeners' chronicle and agricultural gazette. London: published for the proprietors, 1844-1873. url , p. 1021, p. 1230, p. 1387.
- The Gardeners' chronicle: a weekly illustrated journal of horticulture and allied subjects. London: [Gardeners Chronicle], 1874-1955. url , p. 116, p. 134, p. 15, p. 156, p. 204, p. 212, p. 216, p. 223, p. 270, p. 307, p. 319, p. 34, p. 435, p. 591, p. 659, p. 67, p. 716, p. 761, p. 88.
- The Illustrated dictionary of gardening: a practical and scientific encyclopaedia of horticulture for gardeners and botanists / edited by George Nicholson. ..; assisted by J.W.H. Trail. .. and J. Garrett. ... London: L. Upcott Gill; 1887-1889. url p. 451.
- The University of Colorado studies. Boulder, University of Colorado. url p. 172.
- The fungi / by Frederick A. Wolf and Frederick T. Wolf. New York: J. Wiley,  url p. 503.
- The identification of trees & shrubs; how to recognize, without previous knowledge of botany, wild or garden trees and shrubs native to the north temperate zone, with 2, 500 diagrams made by the author. New York, Dutton url p. 272.
- The parks, promenades, & gardens of Paris, described and considered in relation to the wants of our own cities, and the public and private gardens. London, J. Murray.1869. url .
- The standard cyclopedia of horticulture; a discussion, for the amateur, and the professional and commercial grower, of the kinds, characteristics and methods of cultivation of the species of plants grown in the regions of the United States a Illustrated with colored plates, four thousand engravings in the text, and ninety-six full-page cuts. New York, Macmillan, 1919 [c1914] url p. 251, p. 254.
- The testing of forest seeds during 25 years, 1887-1912. Copenhagen, Langkjærs Bogtrykkeri, 1915 url p. 52.
- The trees of Great Britain & Ireland / by Henry John Elwes and Augustine Henry. Edinburgh: Priv. print., 1906-13. url , p. 1949, p. 936, p. 949, p. 950, p. 952.
- Town planting and the trees, shrubs, herbaceous and other plants that are best adapted for resisting smoke. London: E.P. Dutton & co.,  url p. 205.
- Transactions of the Academy of Science of St. Louis. [St. Louis: Academy of Science of St. Louis], 1860-1958. url p. 166, p. 166.
- Transactions of the Royal Scottish Arboricultural Society. Edinburgh: Douglas & Foulis, 1888-1926. url p. 266.
- Trees, shrubs and vines of the northeastern United States. .. together with an account of the principal foreign hardy trees, shrubs and vines cultivated in our country, and found in Central Park, New York City by H.E. Parkhurst. New York, C. Scribner's sons, 1903. url p. 357.
- Webster's Practical forestry: a popular handbook on the rearing and growth of trees for profit or ornament / by A.D. Webster. London: W. Rider & son, limited,  url p. 137.
- Webster's practical forestry: a popular handbook on the rearing and growth of trees for profit or ornament. By A.D. Webster. .. London, W. Rider & Son, Limited[pref. 1905] url p. 55.
- Li Pei-chun & Cheng Sze-hsu. 1979. Betulaceae. In: Kuang Ko-zen & Li Pei-chun, eds., Fl. Reipubl. Popularis Sin. 21: 44-137.
- Furlow, J. J. 1979. The systematics of the American species of Alnus (Betulaceae). Rhodora 81: 1--121, 151--248.
- Hylander, N. 1957. On cut-leaved and small-leaved forms of Alnus glutinosa and A. incana. Svensk Bot. Tidskr. 51: 437--453.
- Murai, S. 1964. Phytotaxonomical and geobotanical studies on gen. Alnus in Japan (III). Taxonomy of whole world species and distribution of each sect. Bull. Gov. Forest Exp. Sta. 171: 1--107.
- Trappe, J. M., J. F. Franklin, R. F. Tarrant, and G. M. Hansen, eds. 1968. Biology of Alder.... Portland.
- Bisby, F.A., Y.R. Roskov, M.A. Ruggiero, T.M. Orrell, L.E. Paglinawan, P.W. Brewer, N. Bailly, J. van Hertum, eds (2007). Species 2000 & ITIS Catalogue of Life: 2007 Annual Checklist. Species 2000: Reading, U.K.
- Brands, S.J. (comp.) 1989-2007. Systema Naturae 2000. The Taxonomicon. Universal Taxonomic Services, Amsterdam, The Netherlands. Accessed March 28, 2007.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 10, 2012.
- Global Biodiversity Information Facility. Accessed March 04, 2008. http://www.gbif.org Mediated distribution data from 7 providers.
- Ruggiero M., Gordon D., Bailly N., Kirk P., Nicolson D. (2011). The Catalogue of Life Taxonomic Classification, Edition 2, Part A. In: Species 2000 & ITIS Catalogue of Life: 2011 Annual Checklist (Bisby F.A., Roskov Y.R., Orrell T.M., Nicolson D., Paglinawan L.E., Bailly N., Kirk P.M., Bourgoin T., Baillargeon G., Ouvrard D., eds). DVD; Species 2000: Reading, UK.
- The International Plant Names Index. Accessed Dec 27, 2011.
- World Checklist of Selected Plant Families. Release date: November 27, 2009
Accessed through GBIF Data Portal March 04, 2008:
- Bundesamt für Naturschutz / Zentralstelle für Phytodiversität Deutschland: Bundesamt fuer Naturschutz / Zentralstelle fuer Phytodiversitaet Deutschland
- Conservatoire botanique national du Bassin parisien: Observations du Conservatoire botanique national du Bassin parisien.
- European Environment Agency: EUNIS
- Forest Research Institute, Department of Natural Forests: Herbarium
- GBIF-Spain: Herbario de la Universidad de Sevilla, SEV
- GBIF-Spain: Institut Botanic de Barcelona, BC
- GBIF-Spain: Real Jardin Botanico (Madrid), Vascular Plant Herbarium (MA)
- GBIF-Spain: Univ. Herbarium SALAMANCA: SALA
- GBIF-Spain: Universidad de Oviedo. Departamento de Biología de Organismos y Sistemas: FCO
- GBIF-Sweden: Herbarium of Oskarshamn (OHN)
- Karl Franzens University of Graz, Insitute for Botany - Herbarium GZU: Herbarium GZU
- UK National Biodiversity Network: Botanical Society of the British Isles - Vascular plant data for Scottish Vice-counties (VCs 80, 84, 103 & 104)
- UK National Biodiversity Network: Botanical Society of the British Isles - Vascular Plants Database
- Biodiversity Heritage Library NamebankID: 1671658
- Catalogue of Life Accepted Name Code: Kew-6294
- Global Biodiversity Information Facility Taxonkey: 4462689
- Globally Unique Identifier: urn:lsid:ipni.org:names:103564-3
- International Plant Names Index (IPNI) ID: 103564-3
- Zipcode Zoo Species Identifier: 644942
- Pei-chun Li & Alexei K. Skvortsov "Betulaceae". in Flora of China Vol. 4 Page 286. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
- "Alnus". in Flora of North America Vol. 3. Oxford University Press. Online at EFloras.org. [back]
- Mean = 111.210 meters (364.862 feet), Standard Deviation = 141.950 based on 742 observations. Altitude information for each observation from British Oceanographic Data Centre. [back]