Four diatoms new to science are described and illustrated: Fragillaria vaucheriae f. contorta nov. fo., Navicula cryptogaster spec. nov., Surirella iowensis spec. nov., Surirella stoermerii spec. nov

Lowe, Rex L.

English

University of Northern Iowa

Proceedings of the Iowa Academy of ScienceVolume 79 | Number Article 81972Notes on Iowa Diatoms X: New and Rare Diatomsfrom IowaRex L. LoweCopyright © Copyright 1972 by the Iowa Academy of Science, Inc.Follow this and additional works at: http://scholarworks.uni.edu/piasThis Research is brought to you for free and open access by UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academyof Science by an authorized editor of UNI ScholarWorks. For more information, please contact scholarworks@uni.edu.Recommended CitationLowe, Rex L. (1972) "Notes on Iowa Diatoms X: New and Rare Diatoms from Iowa," Proceedings of the Iowa Academy of Science: Vol.79: No. 2 , Article 8.Available at: http://scholarworks.uni.edu/pias/vol79/iss2/866 Pnoc. low A AcAu. Ser. 79 ( 1972-1973) Notes on Iowa Diatoms X: New and Rare Diatoms from Iowa DR. REX L. LOWE SYNOPSIS: Diatom species new to Iowa are illustrated. Four diatoms new to science are described and illustrated: Fragillaria INTRODUCTION In the past ten years the diatom flora of Iowa has been under intensive investigation at Iowa State University, re-sulting in several doctoral dissertations and many scientific publications. "Notes on Iowa diatoms" was begun by Dodd and Stoermer ( 1962); this paper continues that series. While examining diatom communities of some central Iowa drainage ditches (Lowe, 1972), several taxa were observed not previously recorded from Iowa, including some that are new to science. Rare species encountered, and new species descriptions, are presented in this paper. Illustrations and, in some cases, descriptions of morphological variability, are in-cluded for each taxon. The diatoms described here were identified from samples collected 'from October, 1967 to May, 1970. Several para-meters of the physical and chemical environment were also determined. These data along with absolute and relative abundances of diatoms observed are found in the original dissertation (Lowe, 1970) and will be published elsewhere (Lowe, 1972). Descriptions of the drainage ditches, referred to here as ditch 1, ditch 2, and ditch 3 are given also. Representative specimens, including holotypes of new taxa, have been deposited in the Iowa Sta'te University (ISC) Diatom Herbarium. Isotypes remain in the author's herbar-ium as well as the Academy of Natural Science (A-G. C.), Philadelphia, Pennsylvania. Systematic Section Fragilariaceae Fragilaria Lyngbye Fragilaria vaucheriae f. contorta nov. fo. Plate 1, figs. 1-20. Frustuales plerumque sola aut in vinculis brevibus acci-dunt. Epistomium lineare ad fines rostratos aliquando capi-tatos subito contrahit. Medium plerumque unilaterale sed non tumidum sicut genus nominatum. Epistomia plerumque flexa non aequaliter. Striae 10 ad 14 in 10 µ, paucae saepe absunt omissae spatia magna inter striae quae adsunt. Frustules usually occur singly or in short chains. Valve linear, narrowing abruptly to rostrate, sometimes capitate, ends. The central area is usually unilateral but is not swollen as is characteristic of the nominate variety. The valves are usually warped in an asymmetric fashion. Striae are 10 to 14 in 10 JL· Often several are absent leaving large spaces between existing striae. The length is from 11 to 35 µ and the breadth from 3 to 6 JL· Holotype: slide 7-4-69 #2 RLL This taxon is referred to as Synedra sp. # 1 in Lowe ( 1972). It was observed in large numbers over a period of three years usually reaching maximum abundance in mid-vaucheriae £. contorta nov. fo. Navicula cryptogaster spec. nov. Surirella iowensi.s spec. nov., Surirella stoermerii spec. nov. July. It was found in great concentrations growing mixed with filamentous green algae. Valves without warped mar-gins were rare in all collections. 13 16 ,_____. I 0 AJ. PLATE I. Figures 1-20. Fragilaria vaucheriae £. contorta Naviculaceae Diploneis Ehrenberg Diploneis elliptica ( Kiitz.) Cl. Plate 2, fig. 6. Slide 11-5-67 #8 duplicate # 1 This taxon was collected in ditch 2 in 1967 in l«uge 11um-bers. It was very rare, however, in collections from the same area during the following two years. I have also collected this taxon from an artesian well in north central Iowa. 1Lowe: Notes on Iowa Diatoms X: New and Rare Diatoms from IowaPublished by UNI ScholarWorks, 1972DIATOMS FROM IOWA 67 ~I 7 Af ~l 4 @' ~1i' 9 '1 10 6 © ~ l ' j II PLATE II. Fig. 1. Stauroneis phoenicenteron var. brunii. Fig. 2. Neidium productum. Fig. 3. Neidium affine var. bonsaensis. Fig. 4. Navicula pseudoreinhardtii. Fig. 5. Navicula cryptocephala f. terrestris. Fig. 6. Diploneis elliptica. Fig. 7. Navicula tenelloides. Fig. 8. Navicula seminulum var. intermedia. Fig. 9. Navicula mutica var. undulata. Fig. 10. Navicula cryptogaster. Fig. 11. Neidium hercynicum f. subrostrata. Fig. 12. Neidium munckii. Nauicula Bory Navicula cryptocephala f. terrestris Lund Plate 2, fig. 5. Slide 3-20-70 #3s This diatom was originally described from a soil flora (Lund, 1945). Its regular occurrence in shallow drainage ditches with ground water sources is not too surprising. Navicuw cryptogaster nov. spec. Plate 2, fig. 10. Epistomia ovata cum finibus contrahen'tibus et teretibus. Spatium angustum secundum axem. Striae intermissae in lateribus utrisque aream lyratam in superficie epistomii faci-unt. Ubique striae paulo radiunt, 26 ad 30 in 10 µ. Longi-tudo 10-13 fl· Latitudo 3-4 fl· Valves elliptical with narrowing rounded ends. Axial area narrow. Striae interrupted on both sides forming a lyrate area on the valve surface. Striae slightly radiate throughout, 26 to 30 in 10 µ. Length 10-13 fl· Breadth 3-4 fl· Holotype: slide 11-14-69 #3 RLL This species is referred to as Navicula sp. #8 in Lowe ( 1972) '. It was never observed in large numbers but ap-peared m several collections from all three ditches. Navicula mutica var. undulata (Hilse) Grun. Plate 2, fig. 9. Slide 5-17-68 #2 T~is taxon ':as encountered only once during this study. Pat:ick and Re.imer. ( 1966) indicate its presence in Maryland, Oh~o an.d California. Reimer ( 1970) noted its presence in moist soil from Cayler Prairie, Iowa. Navicula pseudoreinhardtii Patr. Plate 2, fig. 4. Slide 2-27-70 #ls This taxon was rare in collections from ditch 2 but com-mon from ditches 1 and 3. Navicul,a seminulum var. intermedia Hus't. Plate 2, fig. 8. Slide 9-19-69 Although N. seminulum was also observed in the collec-tions, var. intermedia is easily separated by the coarseness and angle of the striae. It was much less abundant than the nominate variety. Navicul,a tenelloides Hust. Plate 2, fig. 7. Slide 11-7-69 #3 I observed only one specimen of this 'taxon which is often reported from soil floras. This taxon was also reported by Fee ( 1967) and Stoermer ( 1962). N eidium Pfitzer Neidium affine var. bonsaensis Foged Plate 2, fig. 3. Slide 4-17-70 #2s This variety, which has not previously been reported from the United States, was found in only one collection. It is easily distinguished by the long rostrate, wedge shaped ends. Neidium hercynicum f. subrostrata Reim. Plate 2, fig. 11. Slide: In the author's herbarium. Only one specimen of this taxon was observed in an Au-gust, 1969 collection from ditch 1. Neidium munckii Foged plate 2, fig. 12. Slide 4-17-70 #2s, duplicate #5 This taxon has not previously been reported from the United States. It was observed rarely from ditch 2. Neidium productum (W. Sm.) Cl. Plate 2, fig. 2. Slide 11-.5-67 #1, duplicate #2 This taxon was observed very rarely only from ditch 2. Pinnularia Ehrenberg Pinnularia biceps f. petersenii Ross Plate 3, fig. 5. Slide 11-5-67 #8 duplicate #5 This taxon was obsereved only rarely at station 2. Pinnuwria flexuosa Cl. Plate 3, fig. 1. Slide 5-2-70 #2-4 This species was very rare. It was collected only from ditch 2 in the spring of 1970. Pinnularia fluminea Patr. Plate 3, fig. 6. Slide 4-10-70 #2s This taxon was referred to as P. sp. #1 in Lowe (1972). It was found in small numbers from station 2 in the spring of 1970. Pinnularia gibba f. subundulata Mayer. Plate 3, fig. 4. Slide 4-3-70 # 2s This species was found in many samples but was never encountered in large numbers. Pinnularia gracilis Hust. Plate 3, fig. 2. Slide 4-17-70 # 2s, duplicate # 3 This was a rare diatom found only at ditch 2. 2Proceedings of the Iowa Academy of Science, Vol. 79 [1972], No. 2, Art. 8http://scholarworks.uni.edu/pias/vol79/iss2/868 PRoc. low A AcAn. Sc1. 79 ( 1972-197:3) Pin.nularia streptoraphe CI. Plate 3, fig. 3. Slide 4-17-70 #2s, duplicate #4 Only a few specimens of this taxon were collected in bot-tom samples from ditch 2. ~ ~ ~ 4 3 2 ' 0 6 5 PLATE III. Fig. 1. Pinnularia flexuosa. Fig. 2. Pinn11laria gracilis. Fig. 3. Pinnularia streptoraphe. Fig. 4. Pinnularia gibba f. s11b-undulata. Fig. 5. Pinnularia biceps f. petersenii. Fig. 6. Pinnularia fluminea. Fig. 7. Pinnularia titusiana. Fig. 8. Pinn11laria torta. Pinnularia titusiana Hagelstein Plate 3, fig. 7. Slide 11-5-67 #8, duplicate #5 This taxon has not previously been reported from the United States. A specimen of this species could not he lo-cated in Hagelstein's 'type material but the illustration from ·his original description (Hagelstein, 1939) leaves no doubt as to the identity of this diatom. The species was collected in large numbers in 1967 from ditdh 2 but has not been observed in later collections. Pinnularia torta (Mann.) Patr. Plate 3, fig. 8. Slide 11-5-67 #8, duplicate #3 Only one specimen of this taxon was collected. Stauroneis Ehrenberg Stauro.neis borrichii (Petersen) Lund Plate 4, fig. 6. Slide 11-7-69 #2 Only a few frustules of this typically soil diatom were ob-served. They were found at all three stations. Stauroneis JJhoenicenteron var. brunii ( M. Perng. & Herih.) 8 ll ie - J ~ ~ i PLATE IV. Fig. 1. Nitzschia speciosa. Fig. 2. Gomphonema in-tricat11m var. vibrio f. subcapitata. Fig. 3. Gomphonema valid11m var. elongata. Fig. 5. Gomphonema montanum var. ac11111inat11m. Fig. 4. Gomphonema t11rris. Fig. 6. Sta11roneis borrichii. Fig. 7. Gumphonema ang11stat11m var. 11nd11lata. Fig. 8. Gomplwnema montan11m var. subclavata. Voigt Plate 2, fig. 1. Slide 4-17-70 #2s, duplicate #6 Only two specimens were collected, both from ditch 2. Gomphonemaceae Gomplwnema Ehr. Gomphoncma angustatum var. 11nd11lata (Greg.) Grn11. Plate 4, fig. 7. Slide 4-17-70 #2s, duplicate #2 Only two specimens of this taxon were observed, hoth of them from ditch 2. Gomphonema intricatwn var. dhrio f. suhcapitata Mayer Plate 4, fig. 2. Slide 11-.5-67 #1, duplicate #1 3Lowe: Notes on Iowa Diatoms X: New and Rare Diatoms from IowaPublished by UNI ScholarWorks, 1972DIATOMS FROM IowA 69 I found only one specimen of this taxon in a collection from a rock surface in a quiet pool in ditch 2. Gomphonema montanum var. acuminatum (Per. & Heribaud) Mayer Plate 4, fig. 5. Slide 11-5-67 #1 A few frustules of this diatom were observed in collections from ditch 2 in 1967. Gomphonema montanum var. subdavata Grun. Plate 4, fig. 8. Slides 5-24-68 # 1 This species was found in moderate numbers in all three ditches with the greatest number of individuals collected in late fall and early winter. This taxon is most easily identified by the undulating raphe. Gomphonema turris Ehr. Plate 4, fig. 4. Slide 11-5-67 #1 Infrequent observations of this diatom were made from col-lections from ditch 2. Gomphonema validum var. elongata Cl. Plate 4, fig. 3. Slide 4-17-70 #4 'Dhis taxon was collected in very small numbers in 1970 only from ditch 2. N itzschiaceae Nitzschia Hassall Nitzschia speciosa Hust. Plate 4, fig. I. Slide 2-27-30 #3s This large Nitzschia species was represented by only two specimens from ditch 3. PLATE V. Fig. 1. Surirerta stoermerii. Figs. 2-3. Surirella iowen-sis. Surirellaceae Surirella Turpin Surirella iowensis spec. nov. Plate 5, <figs. 2 and 3. Cellae hetropolares, aliquantulum firmiter tortae axibus transapidbus. Valvae ovoidae late tereto polo "capite" et firmius tereto polo "pede"; longitudo 17-54, latitudo I0-25 µ . A.\ae 1?arum cretae, "fenestrae" non apertae. Canales alares 5-7 in IO µ, extendents in media valva u'bi pseudoraphe an-gusto interrumpuntur. Superficies partis mediae valvae stri-atae, striae fere 18 in IO µ. Cells heteropolar, more or less torsioned about the trans-apical axis. Valves ovoid, with broadly rounded headpole and more narrowly rounded footpole, 17-54 µ long, 10-25 µ broad. Wings little developed, "windows" not apparent. Wing canals 5-7 in IO µ, extending .to center of valve where they are interrupted by a narrow pseudoraphe. Sur-face of central portion df valve striate, striae about 18 in IO P.· Holotype: slide 5-3-68 #1 RLL In 1968 S. iowensis was a dominant bottom form in ditch I. It comprised over 50% o'f the population at this time and was most abundant in collections from the ditch bottom. Stoermer ( 1963) reports this taxon to be widely distributed in Iowa, including bo'th East and West Lake Okdboji, Silver Lake fen, Des Moines river, Little Sioux river, and Squaw creek at Ames. Surirella stoennerii spec. nov. Plate 5, fig. I. Epistomium ovatum. Alae distinctae et parallelae in epis-tomio medio ad apicies valde radiant, 2 ad 3 in IO µ. Alae in aream mediam planam et glebosam mergunt. Axis apiciei notata pseudorapha angusta. Longitudo 41-48 µ. Lati'tudo 14-16 P.· Valve ovate. Alae distinct, parallel in .the center of the valve and strongly radiate at the apices, 2-3 in IO µ. Alae merge into a flat granular central area. Apical axis marked by a narrow pseudoraphe. Length 41-48 µ, breadth 14-16 P.· Holotype: slide 11-5-67 #4 RLL Surirella stoennerii is named in honor of Dr. Eugene F. Stoermer, the first investigator at Iowa State University to describe in detail a diatom flora in Iowa. ACKNOWLEDGMENTS I wish to thank Drs. Ruth Pah·ick and Charles Reimer for their assis·tance and hospitality at the Philadelphia Academy of Natural Science. Dr. John Dodd, who advised me through-out this project, also receives my gratitude. The Latin de-scriptions were prepared with the aid of Richard Hebein, Bowling Green State University, Ohio. LITERATURE CITED Dooo, J. D . and E. F. STOERMER. 1962. Notes on Iowa diatoms. I. An interesting collection from a moss-lichen habitat. Proc. Iowa Acad. Sci. 69:83-87. FEE, E. J. 1967. The diatoms in a small Iowa creek. Iowa State J. Sci. 41:393-411. HAGELSTEIN, R. 1939. The Diatomaceae of Puerto Rico and the Virgin Islands. New York Acad. Sci. Survey of Peurto Rico and Virgin Islands 8:313-350. LowE, R. L. 1970. Taxonomic and ecological analyses of diatom communities in drainage ditches. Unpubl. Ph.D . diss., Iowa State Univ., Ames. ____ . 1972. Population dynamics of diatom communities in central Iowa drainage ditches. Iowa State ]. Sci. In press. LUND, J. W. G. 1945. Observations of soil algae. I. The ecology, size and taxonomy of British soil diatoms. I. New Phytol. 45: 196-219. PATRICK R. and C. REIMER. 1966. The diatoms of the United States'. Vol. 1. Acad. Nat. Sci. Phila., Monog. 13. REThiER, C. 1970. Some diatoms ( Bacillariophyceae) from Cayler Prairie. Nova Hedw. 31:235-249. STOERMER, E. F. 1962. Notes on Iowa diatoms. II. Species dis-tribution in a subaerial habitat. Proc. Iowa Acad. Sci. 69:87-96. __ . 1963. Post-pleistocene diatoms from Lake West Okoboji, Iowa. Unpubl. Ph.D. diss., Iowa State Univ., Ames. 4Proceedings of the Iowa Academy of Science, Vol. 79 [1972], No. 2, Art. 8http://scholarworks.uni.edu/pias/vol79/iss2/8

Notes on Iowa Diatoms X: New and Rare Diatoms from Iowa

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Notes on Iowa Diatoms X: New and Rare Diatoms from Iowa

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