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. VOLUME NUMBER AMERICAN FERN JOURNAL: 67 83 2 (1993) A Undescribed Previously hawaiiensis: Isoetes from Hawaii Quillwort W. Carl Taylor Milwaukee Museum, 800 W. Wells Milwaukee, Wisconsin 53233 Public Si., W. Wagner, H. Jr. Ann Michigan 48109 Herbarium, University of Micliigan, Arbor, Hobdy Robert W. Land and Natural Resources, 54 S. High St., Wailuku, Hawaii 96793 Warshauer R. F. RO. Box Volcano, Hawaii 96785 192, from botanists The pteridophytes of Hawaii have received relatively little attention have during the past half-century. However, intensive recent studies in the islands named revealed a number of previously undescribed species, including the quillwort here. Between 25 Quillworts have been found Hawaii several times since early this century. in from pools atop September and 17 October 1917, Charles N. Forbes discovered Isoetes Eke Maui M. BISH). Forbes did not recognize his col- Mt. on of (Forbes 682. Uie island E when R. Warshauer collected be was not 17 October 1977, lection to Isoetes. until It & Hawaii (Warshauer Mauna Kea on island of Isoetes from the east slope of the was quillwort a native McEldowney 1500 BISH), Hawaiian botanists realized there that Eke on summit of Mt. Robert W. Hobdy again discovered Isoetes in pools the in Uie flora. same more from once the site on 23 October 1980 (Hobdy 931 BISH), and he collected it and specimens MIL 5658 and Eke Mt. (Taylor 5332, species Isoetes & - Holotype W. C. Taylor W. H. Wagner, sp. nov. M Mt. Eke. Forbes 682. fusiformis subglobosum Sporangium cm ± dimidio tegens. usque ad 25 longa, virenlia, gracilia, numerosas mm ±10-20 megasporas vel ±2-3 non pigmentifero, diametro, pariete manifeste obscure vel 475-650 diametro, [an Megasporae microsporas albae, continens. 30-4^ brunneae, Microsporac pallide 1-4) fusiform or cylindrical brown, subglobose to Rootstock Roots accommodate spo toward base to abruptly dilated diameter, arranged rangium, gradually tapered to apex, spirally mm wall ±2-3 diameter, in Sporangium subgloblose, Megaspores numerous microspores. rO-20 mecasnores or um 30-4 Microspores brown, light VOLUME NUMBER AMERICAN FERN JOURNAL: 83 2 (1993) 68 4J -ndVJn v_F Figs. 1-6. Isoetes hav^'aiiensis plants, spores, chromosomes, and of hawaiiensis habitats. Fig. Tliree plants 1. /. pool SEM J |iin. Fig. 3. photomicrograph of two hem /. |iin. Fig. 4. Brightfield photomicropraDh of/, /wk Qiromosomes lip squash. stained wiUi Wiltman's hematoxylin. Fig. Shallow ponds on summit of Mt. Eke 5. ensis. V\g, 6. hawaiiemis rooted /. QUILLWORT FROM TAYLOR HAWAII 69 ETAL.: hawaiiensis known only from top of Mt. Eke on the island of Presently, Isoetes is tlie Mauna Kea Maui and from slope of on the island of Hawaii. the east Mt. Eke, a peak on the northeast side of the West Maui Mountains, is shrouded in near- m 6000 Annual estimated be about perpetual mists 1375 elevation. precipitation is to ly at mm. Mt. Eke's summit the remnant core of a volcanic trachyte dome, roughly circular is shape and topped flat ponds approximately 100,000 summit of Mt. Eke about 0.4 hectares in area, harbor the total and appear be only habitat for Isoetes in this region. individuals of hawaiiensis, to the /. some of Aldiough the shallow ponds on Mt. Eke appear to hold water most of llie time, the ponds occasionally are witliout standing water. Similar ponds at higher and lower elc- Mau montane bogs of west Mt and intertwined 10-15 with roots individuals Uieir The lawn largest impression of a sparse (Fig. distance, Uiese aggregations give the 6). 8-10 cm The pond margins, which are most subject occur water averaging deep. plants in to periodic drying, are usually devoid of Isoetes. Mauna Kea located of arc in known on slope The populations of hawaiiensis the east /. m montane about 850 elevation, two adjacent stream channels within a rainforest at grow km about 50 100 plants approximately 17 norUiwest of Hilo. At Uiis location, to stream courses. rock forming the lava close together several patches attached to in mm. 7600 be about Annual area estimated to precipitation in this is and extensive, polymorphic rootstock its Noteworthy of hawaiiensis are features its /. species. unifonn shape for a particular usually in matted Rootstocks of Isoetes are roots. more horizontally may grow centimeter or eiUicr a However, rootstocks of hawaiiensis /. cylindrical root- Occasionally, become become cylindrical. fusiform or vertically to to Roots of or variously lobed. /. and clavately lobed, stocks are dilated distally are clavate, Such exten- of plant. longer than the rest tlie numerous, and often hawaiiensis are slender, mud. These roots are anchor plants securely in soft needed sive roots are probably to plant species continent or island. brought from a distant and divergence of plants isolation genetic deposited arrn Progenitors of hawaiiensis possibly /. Tins known Mallard to eat Isoetes. For example, the is bodies of migratory waterfowl. m breedmg ground.s from presumably Hawaiian Islands its duck occasionally reaches the Canada Goose, which also has 227-233). Tlic western North America (Berger, 1981. p. lowland wetlands. Hawaiian the an iiTCgular visitor to been observed devour to Isoetes, is While North American .,..„—.. . - appear be of Isoetes to American species ^_ __„... , no records of ducks or geese fre- are quitrdimTemVoTn Second, there I'/imv^/irt.^/.v. Eke region. summits quenting Mt. Eke or the west forest in tlie come from L taiwa- have the could hawaiiensis seems more progenitor of a It likely /. cold water, group of high elevation, complex a nensis complex. The taiwanensis is /. New Taiwan Zealand from to rim western Pacific island species occurring along the a basic taiwanensis is & hawaiien.us, For example, like I. (Britton Brunlon, 1991). /. taiwa- Furthcnnore. microspores. megaspores and echinate /. diploid. also has rugulatc It NUMBER VOLUME AMERICAN FERN JOURNAL: 83 2 (1993) 70 pond on norUiern Taiwan near the top of an extinct vol- shallow nensis occurs in a small, m Whereas Isoetes taiwonensis is dis- 1000 (DeVol, 1972). cano an elevaUon of about at megas- corm, and smaller from hawaiiensis by lack of a velum, irilobed tinguishable its /. pm 400 diameter and less than 30 ^tm which average Uian in pores and microspores less chromosome number, taiwanensis similar to hawaiiensis in in length, respectively, is /. /. complex An from taiwanensis hawaiiensis and ancestor of/, tlie spore textures, habitat. /. Golden Plover which winters could have reached the Hawaiian Islands via the Pacific New Zealand, from China, Taiwan, and the Hawaiian Islands south to Australia, India, breeding grounds on the tundra Samoa, and Oceania. In spring this plover migrates to its abundant The Golden Plover an Pacific is of northern Siberia (Johnscard, 1981, p. 135). Mt grows(Berger, 1981,p. 231). LEDGMENTS We Botany Department, Bishop Museum, William R. from Jane A. Medler, are grateful for as.sistance Hawaii-Manoa, K. Frey, Anderson, Herbarium, University of Micliigan, Daniel D. Palmer, University of Jill University of Wisconsin- Milwaukee, and Qien-Meng Kuo, National Taiwan University. CmzD Literature Berger, Andrew 1981. Hawaiian Birdlife, 2nd ed. University of Hawaii Press, Honolulu, Hawaii. J. Britton, Donald M. and Daniel Brunton. 1991. The spores and affinities of Isoetes taiwanensis F. Fern Gaz. 14:73-81. (Isoetaceae: Pteridojjliyla). DeVol, Charles E. 1972. Isoetes found on Taiwan. Taiwania 17:1-7. JoHNSGARD, Paul A. 1981. The Plovers, Sandpipers, and Snipes of World. University of Nebraska Press, tlie Lincoln, Nebraska.