The North American charophytes have been studied for more than one hundred years
(from Allen, 1880 to Mann, et al., 1999). Still, there is much to find out, both concerning which
species occur and their ecology and distribution. There is no modern flora covering the group in
North America and my determinations are based on common knowledge of the group, and
especially three articles which together cover the different genera of charophytes (Robinson,
1906, Allen, 1954, and Wood, 1948). Later works by the eminent American charologist Richard
D. Wood (Wood 1965, 1968) have a species concept which is different from that which is in
common use today. In Wood (1965) the number of species is reduced from 395 to 81, but the
“old” species are still partly found as forms or microspecies. The descriptions of these are
useful. Excellent drawings of many species can be found in Wood and Imahori (1964).
Florida is a tropical part of USA. The soil is rich in lime, and in the Orlando area there
are a great number of lakes of different sizes. One should therefore expect to find charophytes in
many of these lakes. All such finds are of interest. Material for determination can be sent to me.
Determined specimens will be kept in the Botanical Museum, University of Oslo (Herb. O).
Specimens can be treated as angiosperms or conserved in 70% alcohol and later put in small
plastic envelopes (without alcohol) and sent.
Visited sites:
1. Florida: Osceola County: Kissimmee: Lake Cecilie, June 29, 2000. A eutrophic medium
lime-rich lake with a fine white sandy bottom. Charophytes were growing in dense, mixed
stands in shallow parts of the lake. Water analyses (analysed in Norway): specific resistance 316
uS/cm, chloride 20 mg/L, and calcium 14 mg/L/
2. Florida: Orange County: Orlando: Lake Crescent (at the entrance to Disney MGM Studios),
June 30, 2000. A mesotrophic lake which presumably is artificial. Nitella was
growing in shallow parts competing with phanerogames and filamentous algae.
3. Orlando: Lake Lucerne, July 1, 2000. Eutrophic lake. No charophytes were found.
4. Orlando: Lake Copeland, July 1, 2000. A strongly polluted lake without charophytes. Lakes
3 and 4 are close to the Orlando Railway Station.
The charophytes found:
1. Nitella transilis T.F. Allen (Icon 308 in Wood & Imahori 1964)
Locality: USA: Florida: Orlando: Lake Crescent July 30, 2000.
Specimens monoecious to 10 cm high, green. Axes to 150 um in diameter. Internodes
1-2x the length of branchlets, to 1 cm. Both sterile and fertile branchlets 6 in a whorl, 2 (3)
furcate, to 0.4 cm long. Primary rays 0.5x of branchlet length, secondaries of 4-5, of which one
is a central secondary ray or antheridium. Dactyls two celled, to 1.2 mm, of which end cell is 50
um. Gametangia solitary, conjoined at (1)-2 node. Oogonium 450 um long. Oronula 100 um
long and 100 um wide. Convolutions 8. Oospore 200 um long, 150 um wide. Brown reticulated
membrane. Fossae 34 um. Antheridium 150 um wide.
Comments:
Nitella transilis is a species very close to
N. tenuissima Kutzing and is separated from this by having much shorter internodes
which gives the species a more compact look. The species has been accepted by Wood (1948,
1949, and 1952). In Wood and Muenscher (1956) it is regarded as a variety of N.
tenuissima. Allen (1954) does not accept it as a species, only as part of the variability of
N. tenuissima. In Wood (1965) it is N. tenuissima f.
transilis (Allen) R.D. Wood.
Ecology:
Lake Crescent is a mesotrophic lake and the
charophytes were found on shallow places inside a belt of different water plants. Wood (1952)
reported the species from three localities -- one oligotrophic lake on sand bottom and two
mesotrophic ponds and sand-muck bottom. The species was associated with
oligotrophic/mesotrophic species such as Nitella flexilis (L.) Agardh, N.
megacarpa T.F. Allen, and Chara braunii Gmelin.
Distribution:
North American species.
2. Nitella leibergii T.F. Allen (Icon 315 in Wood & Imahori 1964)
Locality: USA: Florida: Orlando: Lake Cecilie June 29, 2000.
Specimens monoecious to 9 cm high, green. Axes to 400 um in diameter. Internodes
1-2x the length of branchlets to 1.5 cm long. Fertile branchlets 7 in a whorl, 1-2-(3)(very few)
furcate, 0.6 cm long. Primaries 0.5x branchlet length, secondaries 7 (short 1/6 of primaries)
again furcate into 1-2 tertiaries. Sterile branchlets 7 in a whorl, 1 and 2 (3) furcate to 1.1 cm.
(Small heads with fertile whorls found on many shoots). Dactyls 4-5, uniformly 2-celled
(end-cell 50 um, penultimate 0.9 mm). Gametangia conjoined at second branchlet nodes.
Without mucus. Oogonia 400 um long, 300 um wide with 7 convolutions. Coronula small.
Oospore 250-300 um long, 200-250 um wide with 5-6 ridges. Membrane granulate. Dark brown
to golden brown oospores. Fossae 50 um. Antheridia unripe, and only found in the small
undeveloped heads on some whorls.
Comments:
This species is or is close to Nitella
gracilis (Smith) Agardh. It differs from this by having strictly 2-celled dactyls. Other
similar species are N. intermedia Nordstedt in Allen and N. minuta
Allen.
Ecology:
Lake Cecilie is a eutrophic lake and
Nitella were growing here in dense stands.
Distribution:
North American species.
3. Chara sejuncta A. Braun (Icons 99 and 100 in Wood & Imahori 1964)
(= C. compacta Robinson)
Locality: USA: Florida: Orlando: Lake Cecilie June 29, 2000.
Plants to 6 cm high, green. Axes 550 um in diameter. Internodes to 1 mm. Cortex
regularly triplostichous, isostichous. Spine-cells solitary to 250 um long, commonly shorter,
acute, at older internodes not visible. Stipulodes in two rows. Upper row to 750 um long, lower
row 250 um. 10-11 branchlets in each whorl, to 1-2x the length of the internodes. Number of
branchlet segments 11. Lowest branchlet segment ecorticate, others corticated. Anterior
bract-cells two, bracteoles two, both as long as the oogonium, posterior bract-cells five?, short, to
150 um long. Monoecious, sejoined. Oogonium 1000 um long; including coronula, 600 um
wide. Antheridium 300 um wide.
Comments:
This is a species similar to the widespread
Chara zeylanica Klein ex. Willd., but differs from this by having sejoined (at
different branchlet nodes) gametangia.
Ecology:
Little is known about this species. In eutrophic Lake
Cecilie a few specimens were found together with Nitella and Chara
gymnopitys. The species is also found in “lakes in the lowlands of the Mississippi
Illinois, opposite St. Louis” (Robinson 1906).
Distribution:
American species, see Allen (1894).
4. Chara gymnopitys A. Braun (Icons 125, 127, 129, and 130 in Wood & Imahori
1964)
(= C. cardias Allen ex. Robinson, C.
coronatiformisRobinson)
Locality: USA: Florida: Orlando: Lake Cecilie June 29, 2000.
Plants 4-15 cm high. Axes to 500 um in diameter. Internodes to 10 mm long. Root
bulbils. Cortex diplostichous to subtriplostichous, isostichous to strongly tylacanthous on
younger internodes. Spine-cells solitary from papillous to as long as stem diameter scattered and
not dominating. On small specimens spine-cells are appressed to the stem both up and down.
Stipulodes in one row (haplostephanous), acute, 900-1250 um long, 100 um wide, 24 stipulodes
in 12 pairs. Number of branchlets in each whorl 9-12, to 10 mm, 0.5-2x the length of internodes.
Number of segments 3-6, end-segment 1-celled, to 1 mm long. Branchlets total ecorticated.
Bract-cells verticillate as long as or longer than the segments. Rich fertile, monoecious,
conjoined at 1-3 segment. Oogonium 850 um long, to 450 um wide. Convolutions 10-13.
Coronula 100 um long, 150 um wide. Oospore 550 um long, 350 um wide, black, 10-13 ridges.
Fossae 50 um. Antheridium 300 um wide.
Comments:
The original description of Chara cardias
was based on material collected in Volusia County in Florida. A similar species, C.
flaccida A. Braun is reported from Latin America (Horn af Rantzien 1950).
Ecology:
According to Zaneveld (1940) Chara gymnopitys
“ is a prominent element in the rice-fields or paddies of the tropics and
subtropics.”
Distribution:
Southeastern coast of USA (Tindall 1966). Asia
(Zaneveld 1940).
References:
Allen, T.F. 1880. The
Characeae of America. Part 1. New York.
Allen, T.F. 1894. Note on Chara sejuncta A. Br. Bull.
Torrey Bot. Club 21: 526.
Horn af Rantzien, H. 1950. Charophyta reported from Latin America.
Arkiv för Botanik 1: 355-411.
Mann, H., Proctor, V.W., and Taylor, A.S. 1999. Towards a
biogeography of North American charophytes. Aust. J. Bot. 47:445-458.
Robinson, C.B. 1906. The Characeae of North America. Bull. New
York Bot. Garden 4: 244-308.
Tindall, D.R. 1966. The Systematics and Ecology of the Characeae
(Chara and Nitella) of the Southwestern United States and Northern
Mexico. Ph.D. Thesis University of Louisville, pp. 134-145/Chara
hydropitys Reichenbach.
Wood, R.D. 1948. A review of the genus Nitella
(Characeae) of North America. Farlowia 3: 331-398.
Wood, R.D. 1949. The Characeae of Woods Hole Region,
Massachusetts. Biol. Bull. 96: 179-203.
Wood, R.D. 1952. An analysis of ecological factors in the
occurrence of Characeae of the Woods Hole Region, Massachusetts. Ecology 33:
104-109.
Wood, R.D. 1964. Monograph of the Characeae. In: Wood, R.D. &
Imahori, K., A revision of the Characeae. Vol. I. 904 pp. J. Cramer, Weinheim.
Wood, R.D. 1967. Charophytes of North America. A Guide to the
Species of Charophyta of North America, Central America, and the West Indies. 72 pp.
University of Rhode Island, Kingston, USA.
Wood, R.D. and Imahori, K. 1964. Iconograph of the Characeae.
In: Wood, R.D. and Imahori, K., A Revision of the Characeae. Vol. II. J. Cramer,
Weinheim.
Wood, R.D. & Muenscher, W.C. 1956. The Characeae of the State
of New York. Mem. 338, Cornell Univ. Agric. Exp. Sta.: 3-77.
Zaneveld, J.S. 1940. The Charophyta of Malaysia and adjacent
countries. Blumea 4: 1-223.
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