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Common Names in Chinese:
Common Names in Dutch:
Common Names in English:
Carolina Mosquito Fern, Carolina Azolla, Carolina Mosquitofern, eastern mosquito fern, Eastern Mosquito-Fern, Fairy-Moss, Mosquito Fern, Mosquito Plant, Mosquito-Plant
Common Names in French:
azolla de Caroline, azolle de Caroline
3--5 cm. Stems prostrate
, 1--3 cm, or nearly erect
, 3--5 cm, hairs
absent. Leaves with 1(--2) -celled hairs on upper surface of upper lobe
in pairs. Megasporocarp megaspore with 3 floats
. Microsporocarp masses entirely covered with arrowlike barbs
Species ca. 7: tropical to temperate regions .
Azolla is divided into sect. Azolla and sect. Rhizosperma (Meyen) Mettenius, which are sometimes recognized as subgenera . New World species belong to sect. Azolla and differ from sect. Rhizosperma by having 3 floats per megasporocarp (fig. 25.1), subdichotomous branching, and straight barbs on microsporangial masses (rather than 9 floats per megasporocarp, pinnate branching, and needlelike hairs or hairs absent on microsporangial masses). The genus was more diverse in past geologic ages: 30 species are known from the Cretaceous (J. W. Hall 1974).
The species of Azolla are difficult taxonomically because (1) about 80% of the specimens lack sori, which are necessary for identification, and (2) the characteristics needed to identify the species are difficult to observe. A scanning electron microscope is needed to see sculpturing of the megaspores, and a light microscope is needed to see the number of cells per hair on the upper leaf lobe. (These hairs are best seen in profile on mature leaves; at least 40× magnification is needed.)
Previous workers emphasized the number of septae (internal partitions) in the barbs on the microsporangial masses as a primary differentiating characteristic among species of Azolla (e.g. , H. K . Svensen 1944). This character is not constant, however, either within a species or within an individual (R. K. Godfrey et al. 1961; L. V. Hill and B . Gopal 1967; K. Seto and T. Nasu 1975). Because nearly all floristic work in North America since the 1940s has been based on Svenson's synoptic treatment, the identity of most specimens is questionable, and therefore ranges are imprecisely known.
The maps for this treatment are tentative. For the most part, I have noted occurrences only in those states or regions from which specimens have been identified using characteristics given in this key . Literature that attributes a particular species of Azolla to a particular state or province must be questioned because the specimens were presumably identified using the inconsistent glochidial characteristics given by H. K. Svenson (1944). More work is needed to determine the distribution of Azolla species in North America.
Agriculturally, Azolla is famous for its symbiosis with the nitrogen-fixing Anabaena azollae Strasburger, a cyanobacterium (blue-green alga ) found at the stem apices, beneath indusia, and in cavities of the upper leaf lobes. Because the plants fix nitrogen, they are often used as a green fertilizer or mixed with livestock feed as a nutritional supplement. Azolla pinnata has been cultivated for many centuries in rice paddies of northern Vietnam and southeastern China, where it acts as a fertilizer after it decomposes.
Azolla is the most frequently studied genus of ferns in the world because of its economic importance. The three North American species are naturalized in Europe and South Africa, and they have been introduced into Hawaii for horticulture and into Asia for agriculture. All species have been studied for agricultural uses in rice-producing areas.
Azolla is usually found in stagnant or slow-moving water of ponds , lakes , marshes, swamps , and streams . Plants turn reddish when under stress, such as from poor nutrition, salinity , or high temperatures . Sporulation needs further investigation.
Species Azolla caroliniana
dark green or with margins
of bright crimson or whole plants
dark red, free-floating or forming multilayer mat to 4 cm thick under
good conditions; plants infrequently fertile
. Stems prostrate
cm. Largest hairs
on upper leaf lobe
near stem with 2 or more cells
broad pedicel cell often 1/2 or more height
of hair, apical cell
, with tip
nearly parallel to leaf surface. Megaspores without
raised angular bumps
or pits, densely and uniformly covered with
The sporophyte of Azolla caroliniana commonly survives throughout the year in temperate areas (with hard frosts and prolonged ice cover ). It is the best adapted of all species for subsistence on mud . Azolla caroliniana is rarely collected with sporocarps . [source]
Flowers: Bloom Period: n/a • Flower Color: inconspicuous, none
Size: under 6" tall.
Typically found at an altitude of 0 to 2,939 meters (0 to 9,642 feet).
Culture: Space 3-6" apart.
Soil: Minimum pH: 4.5 • Maximum pH: .1
Sunlight: Sun Exposure: Full Sun .
Temperature: Cold Hardiness: 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11. (map)
- Chatton, 1925
- Haeckel, 1866
- Cavalier-Smith, 1981
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Kenrick & Crane, 1997, nom. inval.
- Kenrick & Crane, 1997, Nom. Nud.
- Cronquist et al., 1966
- Britton, 1901
- Water Ferns
- Family: Salviniaceae () - Lestiboudois, 1826
- Order: Salviniales () - Britton, 1901 - Water Ferns
- Class: Polypodiopsida () - Cronquist et al., 1966
- Infraphylum: Moniliformopses () - Kenrick & Crane, 1997, Nom. Nud.
- Subphylum: Euphyllophytina () - Kenrick & Crane, 1997, nom. inval.
- Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
- Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
- Kingdom: Plantae () - Haeckel, 1866 - Plants
: Willd. Publication
Pl., ed. 4 [Willdenow]
5: 541 1810
Name Status: Accepted Name .
Last scrutiny: 15-Mar-2000
Members of the genus Azolla
ZipcodeZoo has pages for 5 species, subspecies, varieties, forms, and cultivars in this genus:
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- A Directory of Neotropical Wetlands. IUCN Conservation Monitoring Centre url p. 344.
- A botanical survey of the Galapagos Islands, by Alban Stewart. San Francisco, California Academy of Sciences, 1911. url p. 27.
- A compendium of the flora of the northern and middle states, containing generic and specific descriptions of all the plants, exclusive of the cryptogamia, hitherto found in the United States, north of the Potomac. New York, S. B. Collins, 1826. url p. 390.
- A contribution to the knowledge of the flora of southeastern Minnesota. [Boston, Heliotype Print. Co.]1900. url p. 355, p. 368, p. 371.
- A guide and key to the aquatic plants of the Southeastern United States, by Don E. Eyles and Lynne Robertson, Jr. With original drawings by Garnet W. Jex. Washington, U. S. Govt. Print. Off., 1963. url p. 141.
- A student's text-book of botany, by Sydney H. Vines. With 483 illustrations. London, Macmillan & co., 1896. url , .
- A student's text-book of botany. London, Sonnenschein, 1894. url p. 62.
- A survey of natural areas in Brunswick County, North Carolina: for The North Carolina Natural Heritage Program, Coastal Natural Area Inventory Project / Raleigh: North Carolina Coastal Energy Impact Program, Office of Coastal Management, North Carolina Dept. of Natural Resources and Community Development, [1982?] url , p. 4.
- Agricultural news. Bridgetown, Barbados, Bowen & sons;1902-22. url p. 107.
- Alien flora of Britain. London, West, Newman, 1905. url p. 200.
- Alpines and bog-plants / by Reginald Farrer. London, Arnold, 1908. url .
- Alpines and bog-plants, London, E. Arnold, 1908. url .
- An elementary text-book of botany, by Sydney H. Vines. .. London: S. Sonnenschein & co., lim.;1898. url p. 377, p. 44.
- An enumeration of the vascular plants known from Surinam: together with their distribution and synonymy / by A. Pulle. Leiden: E. J. Brill, 1906. url p. 37, p. 513.
- An illustrated flora of the northern United States, Canada and the British possessions: from Newfoundland to the parallel of the southern boundary of Virginia and from the Atlantic Ocean westward to the 102nd meridian / by Nathaniel Lord Britton and Hon. Addison Brown. New York: Scribner, 1913. url p. 38.
- Annotated list of the ferns and flowering plants of New York state, by Homer D. House. Albany, The University of the state of New York, 1924. url p. 32.
- Annual report / Albany: University of the State of New York, 1902-1918. url p. 18, p. 27.
- Annual report Missouri Botanical Garden. 20 1909 St. Louis: Board of Trustees, 1890-1912. url p. 167, p. 250.
- Annual report of the Ohio State Academy of Science. Columbus: The Academy, 1893-1930. url p. 296.
- Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. Albany, Regents of the University of the State of New York. url p. 203.
- Aquatic and wetland plants of southwestern United States, by Donovan S. Correll and Helen B. Correll. [Washington]Environmental Protection Agency; [For sale by the Supt. of Docs., U.S. Govt. Print. Off.]1972. url p. 59, p. 60.
- Bartonia;proceedings of the Philadelphia botanical club. .. 59 1996 Philadelphia, Philadelphia Botanical Club, Academy of Natural Sciences. url p. 140, p. 23, p. 28, p. 46, p. 48.
- Beautiful flowers and how to grow them, by Horace J. Wright & Walter P. Wright. Illustrated with 32 plates in full colours from paintings by Beatrice Parsons, Eleanor Fortesque Brickdale, Hugh L. Norris, Margaret Waterfield, A. Fairfax Muck 1922 Edinburgh, T.C. & E.C. Jack, ltd., 1922. url index, page 399.
- Brigham Young University science bulletin. 9 1967 Provo, Utah: Brigham Young University, [1955-1976] url p. 25.
- British plants: their biology and ecology / by J. F. Bevis and H. J. Jeffery. London: A. Rivers, 1911. url p. 238, p. 238, p. 320.
- British plants; their biology and ecology, London, Methuen url .
- Brooklyn Botanic Garden record. 16 1927 [Brooklyn]: Brooklyn Botanic Garden, 1912-44. url p. 103, p. 129, p. 147.
- Bulletin / Ohio Biological Survey. Columbus, Ohio: Ohio State University, 1913- url p. 134.
- Bulletin of miscellaneous information. Additional Series. Royal Gardens, Kew. 10 1920 [Kew, Surrey: Royal Botanic Gardens], 1898-1936; url p. 359.
- Bulletin of the Charleston Museum. [Charleston, S.C.: the Museum], 1907-1922. url , p. 24.
- Bulletin of the Torrey Botanical Club. 33 1906 New York: Torrey Botanical Club, 1870-1996 url p. 484, p. 618, p. 620, p. 632.
- Bulletin of the U.S. Department of Agriculture. [Washington, D.C.?]: Supt. of Docs., G.P.O., 1913-1923. url p. 10, p. 4.
- Bulletin of the United States Fish Commission. Washington, The Commission, Govt. Print. Off. url p. 452.
- Cassell's dictionary of practical gardening; an illustrated encyclopædia of practical horticulture for all classes; ed. by Walter P. Wright. London, Cassell and company, limited, 1902. url p. 66.
- Catalog of Ohio vascular plants, arranged according to the phyletic classification; with notes on the geographical distribution in the state, based mainly on specimens in the State Herbarium, Botanical Laboratory, the Ohio State Univ Columbus, The Ohio State University, 1914. url .
- Catalogue of scientific papers (1800-1900) Comp. by the Royal society of London. Cambridge, C. J. Clay and sons, 1867-1902; url p. 1003, p. 20, p. 774, p. 777.
- Catalogue of scientific papers, 1800-1900. Compiled by the Royal Society of London. London, C.J. Clay and Sons, 1867-1902 [etc.] Cambridge, Cambridge University Press, 1914-25. url p. 20, p. 777.
- Contributions from the United States National Herbarium 3 1892-1896 Washington, D.C.: Smithsonian Institution Press, 1890- url p. 193, p. 226, p. 27, p. 293, p. 303, p. 320, p. 369, p. 39, p. 68, p. 84.
- Diseases of plants induced by cryptogamic parasites: introduction to the study of pathogenic Fungi, slime-Fungi, bacteria, & Algae / London; Longmans, Green & co., 1897. url .
- Ecology and behavior of the Manatee (Trichechus manatus) in Florida / by Daniel S. Hartman. [Pittsburgh, Pa.]: American Society of Mammalogists, 1979. url p. 11, p. 47.
- Entomological news. [Philadelphia]American Entomological Society, 1925- url p. 294.
- Erigenia: journal of the Illinois Native Plant Society. Carbondale, Ill.: The Society, 1982- url p. 51.
- Experiment station record. Washington: G.P.O., 1889-1946. url p. 827.
- Ferns and fern allies of Canada / [Ottawa]: Research Branch, Agriculture Canada, 1989. url p. 310, p. 312, p. 391, p. 418.
- Ferns and fern allies of Guatemala. Robert G. Stolze. 12 1983 Chicago, Ill.: Field Museum of Natural History, 1983. url p. 10, p. 8.
- Flora Peoriana; the vegetation in the climate of middle Illinois. Peoria, Ill., J. W. Franks, 1887. url p. 65, p. 79.
- Flora of Indiana, by Charles C. Deam. Indianapolis, Wm. B. Burford printing co., contractor for state printing and binding, 1940. url p. 59.
- Flora of Kwangtung and Hongkong (China) being an account of the floweriing plants, ferns and fern allies together with keys for their determination preceded by a map and introduction, London, H. M. Stationery off., printed by Darling and son, ltd., 1912. url .
- Flora of Nebraska; a list of the ferns, conifers and flowering plants of the state with keys for their determination. Plainview, Neb., 1923 url p. 12.
- Flora of New Mexico / by E.O. Wooton and Paul C. Standley. Washington: G.P.O., 1915. url p. 27.
- Flora of the Lancetilla Valley, Honduras, by Paul C. Standley. 10 1931 Chicago, Field Museum of Natural History, 1931. url p. 83.
- Flora of the Rocky Mountains and adjacent plains, Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and neighboring parts of Nebraska, South Dakota, North Dakota, and British Columbia / by P.A. Rydberg. New York: The author, 1922. url p. 1051.
- Flora of the state of Washington / by Charles V. Piper. Washington: G.P.O., 1906 url p. 84.
- Flora of the state of Washington. By Charles V. Piper. Washington, Govt. Print. Off., 1906. url p. 84.
- Flora of the vicinity of New York; a contribution to plant geography. [New York]1915 url p. 62.
- Florists' review Chicago: Florists' Pub. Co. url .
- Flowerless plants: how and where they grow, London, Cassell and Co., Ltd., 1913. url , .
- Goldfish breeds and other aquarium fishes, their care and propagation: a guide to freshwater and marine aquaria, their fauna, flora and management. With 280 explanatory illustrations, printed with the text / by Herman T. Wolf... Philadelphia: Innes & sons, [c1908] url p. 209.
- Goldfish varieties and tropical aquarium fishes; a complete guide to aquaria and related subjects, Philadelphia, Innes url .
- Great Basin naturalist memoirs. 1981 [Provo, Utah]Brigham Young University, 1976-1992. url p. 83.
- Hand-list of ferns and fern allies cultivated in the Royal Botanic Gardens. London, Printed for H. M. Stationery Off., by Darling, 1906. url p. 145, p. 145.
- Handbook of practical botany for the botanical laboratory and private student / by E. Strasburger; translated and edited from the German with many additional notes by W. Hillhouse. London: Macmillan, 1900. url p. 255, p. 261.
- How to know the ferns / by S. Leonard Bastin. London: Methuen & Co.,  url , p. 110.
- Index filicum: a synopsis, with characters, of the genera, and an enumeration of the species of ferns, with synonymes, references, &c., &c. London, W. Pamplin, 1857-62. url , , p. 189.
- International catalogue of scientific literature. London: Published for the International Council by the Royal Society of London, 1902-1919. url p. 182, p. 191, p. 883, p. 182, p. 582, p. 61, p. 689, p. 883.
- Introduction to cytology, by Lester W. Sharp. .. New York, McGraw-Hill Book Company, inc., 1934. url p. 138.
- Journal of botany, British and foreign. London: Robert Hardwicke, 1863-1942. url p. 210, p. 211, p. 212, p. 249, p. 269, p. 270, p. 28, p. 332, p. 381, p. 385, p. 385, p. 389.
- Journal of ethnobiology. 21 2001 Flagstaff, Ariz.: Center for Western Studies, 1981- url figure 1, p. 59, p. 60.
- Journal of the New York Botanical Garden. 10 1909 Lancaster, Pa.: Published for the Garden by the New Era Printing Co., 1900- url p. 216, p. 43.
- Journal of the Royal Microscopical Society. Oxford [etc.]Royal Microscopical Society. url , p. 201, p. 203, p. 227, p. 331, p. 363, p. 50, p. 520, p. 819, p. 915.
- Journal of the Washington Academy of Sciences. Washington [etc., Washington Academy of Sciences] url p. 238.
- Key to the Rocky Mountain flora; Colorado, Utah, Wyoming, Idaho, Montana, Saskatchewan, Alberta, and parts of Nebraska, South Dakota, North Dakota, and British Columbia. New York, 1919. url p. 283.
- La Mortola: a short description of the garden of Thomas Hanbury, Esq. / by Friedrich A. Flückiger; translated from the German by Helen P. Sharpe. [s.l.]: Privately printed, 1885. url p. 7.
- Manual of plant diseases, Wilkes-Barré, Pa., The Record press, c1914-22 url p. 11.
- Minnesota botanical studies. Minneapolis, Geological and Natural History Survey of Minnesota. url , p. 255, p. 355, p. 355, p. 368, p. 368, p. 371, p. 371, p. 749, p. 749.
- Natural areas inventory, Gates County, North Carolina / Raleigh: North Carolina Coastal Energy Impact Program, Office of Coastal Management, North Carolina Dept. of Natural Resources and Community Development,  url p. 147.
- Nature. London, etc., Macmillan Journals Ltd., etc. url p. 24, p. 327, p. 8.
- New York State Museum bulletin. Albany, N.Y.: University of the State of New York, 1916-1944. url p. 18, p. 27, p. 66, p. 69.
- Organography of plants, especially of the archegoniatae and spermaphyta, ed. by Isaac Bayley Balfour. Oxford, Clar. Press, 1900-5. url p. 211.
- Outlines of classification and special morphology of plants, by K. Goebel. A new ed. of Sachs' Text-book of botany, book II, authorized English translation by Henry E. F. Garnsey; rev. by Isaac Bayley Balfour. With 407 woodcuts. Oxford, Clarendon Press, 1887. url p. 235, p. 237, p. 239, p. 239.
- Physiological plant anatomy, tr. by Montagu Drummond. London, MacMillan, 1914. url p. 469.
- Phytogeography of Nebraska. 1. General survey by Roscoe Pound and Frederic E. Clements. Lincoln, Neb.Published by the Seminar1900 url p. 179, p. 80.
- Phytologia. Bronx Park, New York, H.A. Gleason and H.N. Moldenke, url p. 114, p. 337.
- Plant culture; a working handbook of every day practice for all who grow flowering and ornamental plants in the garden and greenhouse, New York, A. T. De La Mare Co., Inc.[c1921] url .
- Plant life of Alabama, an account of the distribution, modes of association, and adaptations of the flora of Alabama, together with a systematic catalogue of the plants growing in the state. By Charles Mohr. .. Montgomery, Ala., Brown printing co., 1901. url p. 125, p. 320.
- Plant life of Alabama: an account of the distribution, modes of association, and adaptations of the flora of Alabama, together with a systematic catalogue of the plants growing in the state / by Charles Mohr. Montgomery, Ala.: Brown Printing Co., 1901. url p. 125.
- Plant morphology. New York, McGraw-Hill, 1953. url p. 301.
- Plants of Iowa; a preliminary list of the native and introduced plants of the state, not under cultivation; comp. by Wesley Greene, secretary. Des Moines, Bishard brothers, printers, 1907. url p. 123, p. 123.
- Practical carp culture / by L.B. Logan. Youngstown, Ohio: L.B. Logan?, 1888? url p. 90.
- Proceedings - California Academy of Sciences, 4th series. San Francisco, California Academy of Sciences. url p. 27.
- Proceedings of the American Academy of Arts and Sciences. Boston: Metcalf and Co., 1846-1958 url p. 115, p. 225.
- Proceedings of the Biological Society of Washington. Washington, Biological Society of Washington url p. 177, p. 198.
- Proceedings of the Cambridge Philosophical Society, Mathematical and physical sciences. Cambridge [etc.]Cambridge Philosophical Society. url p. 383, p. 384, p. 385, p. 386.
- Proceedings of the Entomological Society of Washington. Washington, etc.: Entomological Society of Washington url p. 185.
- Proceedings of the South London Entomological & Natural History Society. London [Eng]: South London Entomological and Natural history Society, [1897-1933] url p. 71.
- Proceedings of the United States National Museum. Washington: Smithsonian Institution Press, [etc.] url p. 645, p. 919.
- Pteridophyta of Peru. Rolla M. Tryon, Robert G. Stolze; with the collaboration of: R. James Hickey, Benjamin Øllgaard. 34 1994 Chicago, Ill.: Field Museum of Natural History, 1994. url p. 10.
- Report of the State Botanist. Albany, N.Y.: University of the State of New York, 1898-1925. url , , , .
- Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean. Made under the direction of the secretary of war, in 1853-. .. 4 1856 Washington, A.O.P. Nicholson, Printer [etc.]1855-60. url p. 161.
- Reports of the Survey. Botanical series. Minneapolis [etc.]1892- url p. 255, p. 355, p. 368, p. 749.
- Special papers / Ohio Academy of Sciences. Columbus, Ohio: The Academy, 1899-1929. url p. 296.
- Species and varieties, their origin by mutation; lectures delivered at the University of California Chicago, The Open Court Publishing Company; [etc., etc.]1906. url , .
- Species and varieties: their origin by mutation / lectures delivered at the University of California by Hugo DeVries; edited by Daniel Trembly MacDougal. Chicago: The Open Court; 1906, c1904. url p. 239, p. 828.
- Species and varieties; their origin by mutation. Lectures delivered at the University of California by Hugo De Vries. Edited by Daniel Trembly MacDougal. Chicago, K. Paul, Trench, Truber, 1906 [c1904] url p. 239, p. 826.
- Syllogeus. Ottawa, National Museum of Natural Sciences, 1972-1995. url p. 18, p. 59, p. 62.
- Taxonomic literature: a selective guide to botanical publications and collections with dates, commentaries and types (TL2) Utrecht: Bohn, Scheltema & Holkema, 1976-1988. url p. 1087.
- Textbook of theoretical botany, by R. C. McLean and W. R. Ivimey-Cook. London, Longmans, Green[1951- url p. 1050, p. 547.
- The American journal of science. 6(2) 1848 New Haven, Kline Geology Laboratory, Yale University. url p. 89.
- The Canadian field-naturalist. Ottawa, Ottawa Field-Naturalists' Club. url , , , p. 409, p. 441, p. 442, p. 443, p. 444, p. 445, p. 447, p. 545, p. 546, p. 687, p. 692, p. 694, p. 702, p. 776, p. 778, p. 780, p. 786.
- The Garden: an illustrated weekly journal of gardening in all its branches. London: [s.n., url p. 117, p. 155, p. 184, p. 262, p. 359, p. 372, p. 41, p. 412, p. 504, p. 504.
- The Gardeners' chronicle: a weekly illustrated journal of horticulture and allied subjects. London: [Gardeners Chronicle], 1874-1955. url , p. 184, p. 196, p. 235, p. 247, p. 248, p. 330, p. 773.
- The Great Basin naturalist. 41 1981 Provo, Utah: M.L. Bean Life Science Museum, Brigham Young University, 1939-1999. url p. 84.
- The Irish naturalist. Dublin: Eason & Son, Ltd., 1892- url p. 206, p. 318.
- The Metaspermae of the Minnesota Valley; a list of the higher seed-producing plants indigenous to the drainage-basin of the Minnesota River, by Conway MacMillan. Minneapolis[Harrison & Smith, State Printers]1892. url p. 26.
- The Metaspermae of the Minnesota valley; a list of the higher seed-producing plants indigenous to the drainage-basin of the Minnesota river. Minneapolis[Harrison & Smith, State Printers]1892 url p. 26.
- The Ohio journal of science. Columbus, Ohio, The Ohio State University and the Ohio Academy of Science url p. 296, p. 297, p. 421.
- The Proceedings of the Iowa Academy of Science. Des moines, Iowa: The Academy, [1889-1987] url p. 314, p. 421.
- The century supplement to the dictionary of gardening, a practical and scientific encyclopaedia of horticulture for gardeners and botanists / by Geo. Nicholson. .. [et al.]. Hyde Park, Mass.: Geo. T. King; 1901. url p. 118.
- The complete aquarium book; the care and breeding of goldfish and tropical fishes, by William T. Innes. .. New York, Halcyon house[c1936] url p. 56.
- The encyclopedia of gardening. A dictionary of cultivated plants, etc., giving in alphabetical sequence the culture and propagation of hardy and half-hardy plants, trees and shrubs, orchids, ferns, fruit, vegetables, hothouse and g London, W. H. & L. Collingridge url .
- The essentials of botany. New York, Holt[c1884] url .
- The essentials of botany. New York: Holt[c1896] url .
- The faunal connections between Europe and North America. New York, Wiley url p. 212, p. 241, p. 342.
- The plankton of the Illinois river, 1894-1899, with introductory notes upon the hydrography of the Illinois river and its basin. By C. A. Kofoid. Urbana, Ill., 1903-08 url p. 241.
- The vegetation of south Florida south of 27 30 north, exclusive of the Florida keys, by John W. Harshberger. Philadelphia, Wagner Free Institute of Science, 1914. url p. 147.
- Torrey, J. Report on the United States and Mexican boundary survey: made under the direction of the secretary of the Interior /by William H. Emory, major First Cavalry, and United States commissioner. 2(1) 1859 Washington: C. Wendell, printer, 1857-59. url p. 236, p. 236.
- Torreya. Burlington, Vt., Torrey Botanical Club, 1901-1945. url , p. 102, p. 109, p. 11, p. 133, p. 14, p. 156, p. 157.
- Transactions of the Kansas Academy of Science Topeka, Kan.: Geo. W. Martin. url p. 292.
- Transactions of the Kentucky Academy of Science. [Lexington, Ky.]Kentucky Academy of Science, 1923-1997. url p. 137, p. 145, p. 48, p. 49.
- Transactions of the Wagner Free Institute of Science of Philadelphia. 7 1910 Philadelphia: Wagner Free Institute of Science of Philadelphia, 1887-1927. url p. 147.
- Tulane studies in zoology and botany. 24 1983 New Orleans: Tulane University, [1968- url , p. 113.
- Tulane studies in zoology. 2 1954 New Orleans: Tulane University, 1953-1968. url p. 17.
- Wrightia. 1 1949 Richardson, Tex. [etc.]University of Texas at Dallas. url p. 253, p. 269.
- Zoe:a biological journal. 1 1890 San Diego, Calif. [etc.]Zoe Publishing Co. url p. 100, p. 383.
- Hall, J. W. 1974. Cretaceous Salviniaceae. Ann. Missouri Bot. Gard. 61: 354--367.
- Lumpkin, T. A. and D. L. Plucknett. 1982b. Botany and ecology. In: T. A. Lumpkin and D. L. Plucknett, eds. 1982. Azolla as a Green Manure: Use and Management in Crop Production. Boulder. Pp. 15--38.
- Moore, A. W. 1969. Azolla: Biology and agronomic significance. Bot. Rev. (Lancaster) 35: 17--35.
- Svenson, H. K. 1944. The New World species of Azolla. Amer. Fern J. 34: 69--84.
- Van Hove, C., T. de Waha Baillonville, H. F. Diara, P. Godard, Y. Mai Kodomi, and N. Sanginga. 1987. Azolla collection and selection. In: International Rice Research Institute. 1987. Azolla Utilization. Proceedings of the Workshop on Azolla Use. Fuzhou, Fujian, China, 31 March--5 April 1985. Los Banos, Laguna, Philippines. Pp. 77--87.
- Zimmerman, W. J., T. A. Lumpkin, and I. Watanabe. 1989. Classification of Azolla spp., section Azolla. Euphytica 43: 223--232.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 10, 2012.
- Biodiversity Heritage Library NamebankID: 2645023
- Catalogue of Life Accepted Name Code: ITS-18008
- Global Biodiversity Information Facility Taxonkey: 13540951
- Globally Unique Identifier: urn:lsid:ipni.org:names:17056910-1
- GRIN Nomen Number: 102986
- Integrated Taxonomic Information System (ITIS) Taxonomic Serial Number (TSN): 18008
- International Plant Names Index (IPNI) ID: 17056910
- Natural Heritage Network Species Identifier: PPAZO01010
- U.S.D.A. Plant Symbol: AZCA
- Zipcode Zoo Species Identifier: 21422