Azolla caroliniana Willd.

  • Authority

    Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.

  • Family

    Salviniaceae

  • Scientific Name

    Azolla caroliniana Willd.

  • Description

    Species Description - Plants minutely frondose, roundish or irregular in outline, the whole plant 0.5-1.5 cm broad and long; stems terete, bearing several lax, filiform roots 1-1.5 cm long, alternately branched. the branches pseudodichotomous. Fronds crowded, imbricate, the upper lobes oval, 0.7-0.9 mm long, 0.5-0.6 mm broad, green, pink, or bronzy red, the upper side convex and very minutely papillose-puberulous, the underside deeply hollow-concave; lower (submerged) lobes larger, pale green and delicately membranous, glabrous. Sporocarps glabrous; megasporangia ovoid-apiculate, 0.4-0.55 mm long; microsporangia numerous (16-66), each usually containing three massulae, with glochidia usually both septate (1-4 septae) and non-septate. (Note: Puerto Rican plants have not yet been found in a fertile condition.)

  • Discussion

    Type. L. C. Richard, from "Carolina" {Herb. Willd. 20260, B, photos GH, US).

    Syn. Azolla portoricensis Sprengel in Linnaeus, Syst. veg. ed. 16,4: 9. 1827. (Type. Bertero s.n., from Puerto Rico, LZ, destroyed; isotype FT, not seen.

    Eastem United States, Greater Antilles, Grenada, Tobago, and Trinidad; widespread in continental tropical America. Distribution in Puerto Rico. Known from nine scattered localities, three near the north coast, three near the south coast, and three from the east-central region (tributaries ofthe Rio Grande de Loiza); recorded from Caguas, Guanica, Guayanilla, Gurabo, Juncos, Manati, Ponce, Toa Baja, and Vega Baja. Habitat. Floating on clear fresh water in drainage canals, ditches, and shallow ponds or lakes at low to lower middle elevations (sea-level-200 m), sporadic but often locally abundant.

  • Distribution

    Eastem United States, Greater Antilles, Grenada, Tobago, and Trinidad; widespread in continental tropical America. Distribution in Puerto Rico.

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