Torrey Botanical Society

Observations on Zizania texana (Texas Wildrice), an Endangered Species Author(s): Edward E. Terrell, William H. P. Emery, Harold E. Beaty Reviewed work(s): Source: Bulletin of the Torrey Botanical Club, Vol. 105, No. 1 (Jan. - Mar., 1978), pp. 50-57 Published by: Torrey Botanical Society Stable URL: http://www.jstor.org/stable/2484263 . Accessed: 18/01/2012 15:35

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AVOL. 105, No. 1, PP. 50-57 JANUARY-AIARCH 1978

Observationson Zizania texana (Texas wildrice), an endangeredspecies

Edward E. Terrell 1 Planit TaxoiioimyLaboratory, Genietiesand GerniplasmnIinstitute, Agricultur-al Research Service, U.S. Departmenitof Agrieulture,Beltsville, Maryland 20705 William H. P. Emery Departmeiit of Biology, SoutlhwestTexas State Uniiversity,Sani Marcos, Texas 78666 and Harold E. Beaty Consultant-Instructorin Ecology, TeimipleJuniior College, Temiple,Texas 76501 TERRELL,E. E. (Plaiit Lab., Plant Geiieties ai1d Geriiiplasi1 Ii1st., U.S. Dept. Agric., Beltsville, MD 20705), W. H. P. EMA-ERY(Dept. Biol., Southwest Texas State Uiniv., Saii Marcos, TX 78666) ancl H. E. BEATY (Temple JuniiorColl., Teim-ple, TX 76501). Observationison Zizania texanta (Texas wildrice), an eindaingeredspecies. Bull. Torrey Bot. Club 105: 50-57. 1978.-ZizWania texana is restricted to 2.4 kill of the upper Saii Marcos River iii southeentral Texas. Physical anid clhemical characteristics of the Saii Marcos River are unusual, being characterized by alkalinie or lieutral pH anci water temperature varying onily ea 5 C annually. Taxoinoimiccoiiparisol of Z. texana with Z. aqtatica and Z. palUtstiis showed several imiiportanit morplhological dif- ferences; these were mnaiiitaiiiecliii cultivatioii, although Z. texana lost its streamiinig, submnersedhabit. Zizania texana is geographically isolated fromiiall other Zizantia taxa by at least 640 knm.Viable seed obtainied in cultivationi produced 500 i1eCW clonies. Humani disturbances have affected Z. texanta adversely. Survival depenids oni continiued water purity and abundant flow fromiiSpring Lake, source of the river. We are at- tempting to preserve the habitat anid to tranisplantcultivated clones to other localities in ceiltral Texas.

Texas wildrice, Zizania texana Hitch- Historical background. The firstdoeu- cock, is of special interest because of its ineinted collection of Zizaiiia texana was rarity and its problematical relationship by G. C. Nealley in August, 1892 (U.S. to otherspecies of Zizania. Curiosityabout 'National Herbarium sheet 979361). It is the validity of the species led the senior labelled Z. aquatica, thus Nealley may not author to visit its native habitat in Sep- have suspected it to be different.A later tember 1973, in companiywith the junlior collection by Eiia A. Allen on July 10, authors,who had published previously on 1921 (US 1611456) was labelled Z. texanta the species. Subsequently,we accumulated apparently by A. S. Hitchcock long after data concerningecology, distribution, inor- its collection. Both of these collections phology, taxonomy,and response to cul- came fronmthe San Mareos River. tivation. The discovery and recognlition of Z. Zizania texana is restricted to a 1.5 texana as a distinctspecies was by W. A. mile (2.4 km) length of the headwatersof Silveus, an attornieyanid amuateurbotainist the San Marcos River, within the city livinigin San- Antonio, Texas. In a letter limits of San Marcos (population ca. (preserved with the holotype in the U.S. 20,000), Hays County,southeentral Texas. NatiolnalHerbariulm) dated April 4, 1932, Formerly,the species occurred also at the Silveus wrote to Agnes Chase, U.S. Na- headwaters of the river in Spring, Lake, tional Herbariunm,reo'ardino onie of his col- but it has been destroyedthere. lecting trips: "I travelled about 180 imiles 1 We wish to thaink the followinigpeople for yesterday and got only one grass-is too contributing iniformiiationor specimenis: W. G. dry-then the frost nipped thenmoff. Dore, Caniada Departmenitof Agriculture; F. W. "At San Mareos iiear a road crossin(,g Gould, Texas A. & M. Uniiversity; Bruce Mae- Bryde, U.S. Fish anid Wildlife Service; aind I founcla great deal of Ziz-ania palutstris, F. M. Uhler, Patuxenit Wildlife Researeh Ceniter. but it was growi,ingyin an uiiexpeeted way Received for publication August 16, 1977. fromnwhat I had read 1about it. The San 50 0040-9618/78/0001-0050$01.20/0? 1978 Torrey Botainieal Club 1978] TERRELL, EMERY AND BEATY: TEXAS WILDRICE 51

Marcos River arises a shortdistance above Marcos and took another look at Zizania this crossing, and as a rule the flow is and found it still blooming.It bloomsfrom about constant,the stream is about 40 ft April to Nov. anyway and the man at the wide and has lots of water-the current pump station on the bank of the lake says rapid. it blooms all year if warm. He says they "This grass was growingin water from clean it out and [it] comes up again im- 1-4 ft deep mostlysome distance fromthe mediately. It covers several acres on lake bank-the plant prostrateon or just under and along streambelow." the surface of the water, and in many of A third letter from Silveus, with com- the the floweringpart of the culm mentssimilar to the above, and apparently 1-2 ft above the water,the stem geniculate sent to A. S. Hitchcock, was quoted by where it left the water, and sometimes Hitchcock (1933) in connection with his rooting at that place. The leaves were as original descriptionof Z. texana. Silveus's much as 5 ft long, about 8-10 mm wide at book (1933) on the grasses of Texas sum- the base and 15-20 mm above, . . . marized general informationabout Z. tex- I could understand if the river ana and included an excellent photograph should rise suddenly and cause this grass of the plant in its native habitat. This to become prostrateon the water, but this original photographaccompanies the holo- stream has a pretty steady flow all the type specimen and is reproduced here time. . . . I had expected to find it [Zi- (Fig. 1), courtesyof the SmithsonianIn- zania] along the margins of the stream stitution. growingmore or less like ." The type collection of Z. texana is in A subsequent letter (Nov. 7, 1932) to the U.S. National Herbarium: W. A. Sil- Mrs. Chase noted, "I came home by San veus 518, April 1932, floatingin San Mar-

Fig. 1. Original photo by Silveus. Zieania texana in San Marcos River. 52 BULLETIN OF THE TORREY BOTANICAL CLUB [VOL. 105 cos River near San Marcos, Hays Co., of the river. Utilizing a floatingframe one Texas (Holotype US 1537174; isotype US metersquare to measurethe area of vegeta- 1720531). It may be inferred from Sil- tive dominance, he found that wildrice veus's letter of April 4 that the type col- plants covered 1,131 m2 of river habitat. lection was gatheredon April 3, 1932. The highest concentrationswere in the Ecology and distribution. The upper extremeupper and lower segmentsof the San Marcos River is a rapidly-flowing, 2.4 km lengthof the river. He did not find usually clear river,some 5-15 m wide and any wildricein Spring Lake. up to ea 4 m deep. For the firstfew kilom- Plants of Z. texana formlarge clumps eters the river flows mostly over a firm or masses which are firmlyrooted in the gravel bottom with many shallow ripples gravel bottom of the river (Figs. 2, 3). alternating with deep pools. Its relative Culnmsand leaves are conmpletelyimmersed narrownessand swiftnessgive it the aspect and long-streaming,in the swift current. of a northerntrout stream. Accumulated Plants are geniculate and produce roots flowrecords for the fifteenyears ending in from the lower nodes (Fig. 4). Silveus 's 1971 show that the water velocityaverages description (1933) and his photograph 157 eu ft/see. (U.S. Dept. of Interior (Fig. 1) inidicatethat formerly,when there 1967-1971; Beaty 1972). The water tem- was less hunian disturbance, culms and perature as it issues from the springs is panicles projected as much as one meter constantat 21.5 C. At the lower end of the above the water. At the presenttime, how- wildrice habitat a range of temperature ever, floweringplants are rarely seen, and from 25.5 C in August to 20.4 C in Feb- when present,do not extendvery far above ruary has been recorded. The water tends the surface (Fig. 5). Plants often grow in to be alkaline or neutral due to the lime- the swiftestcurrents of the shallow areas stone source: reported pH in San Marcos near the middle of the river. Other plants Springs is 6.9-7.8 (Texas Water Devel. are in water 2-3 m deep, and the stream- Board 1968). Two readings taken during ing leaves remain below the surface, the the presentstudy were pH 7.4 and 7.9. clear water allowing passage of sufficient Spring Lake (altitude 189 m) was cre- light for photosynthesis. ated over fiftyyears ago by the damming In the upper 0.4 km of the portion of of the San Marcos River not far below the the river inhabitatedby the wildrice,asso- springswhich formits source. The springs ciated species include Potamogeton illtno- discharge 200 million gallons of water ensis Morong, Vallisneria americana daily from the Edwards limestonewhere Michx., Sagittaria platyphylla (Engelm.) it is faulted against the Pecan Gap Chalk. J. G. Sm., and Hydrilla verticillata (L. f.) Due to the clarity of its water, Spring Royle. Throughoutmost of the remaining Lake is now the site of a major touristat- 2.0 km of the habitat the Texas wildrice is traction, Aquarena Springs, Inc., featur- most frequently in isolated clumps, and ing glass-bottomedboat rides and a sub- competitionfrom other species is of minor marine theater. importance. At the time it was discoveredZ. texana The origin of Z. texana poses interest- was very abundant in the San Marcos ing but difficultproblems. In view of its River, in contiguous irrigationlditches, morphologicaldifferences we suppose that and in Spring Lake, requiring consider- Z. texana evolved its differencesover a able effortby the irrigation company to substantial period of time. It may have keep the luxuriant growth under control evolved in geographic isolation, as there (Silveus 1933). Thirty four years later its are no other populations of any Zizania abundance had been drastically reduced. taxon in Texas. The nearest populations of Emery (1967) found only one plant in Z. aquatica are in southern Louisiana, Spring Lake, no plants in the uppermost about 400 miles (640 km) to the east. Like 0.8 km of the San Marcos River, and scat- other southeastern Coastal Plain popula- tered plants in the next 2.4 km. In 1970 tions of Z. aquatica, these plants are quite Emery surveyed the lower reaches of the differentmorphologically from Z. texana. riverby boat, but he did not findany wild- They are giant grasses to 4 m higyh,with rice. only their lower culms immersedand with In 1976 Emery again checked on the leaves 3-5 times broader than those of abundance of wildrice in the upper parts Z. texana. The nearest populations of Z. 1978] TERRELL, EMERY AND BEATY: TEXAS WILDRICE 53

Figs. 2-3. Immersed plants of Zizania texana in San Marcos River. Figs. 4-5. Zizania texana: plant taken from San Marcos River showing rooting at lower nodes; plant with immature inflorescences growing in San Marcos River. palustris are several hundred miles to the long, 1-10 cm wide, with staminate north and northeast,in Missouri, Kansas, branches below, pistillate branches above. and Arkansas. Staminate branches ascending or some- Morphology and taxonomy. The fol- what spreading, to 10 cm long, pedicels lowing description of Z. texana includes 1-9 mm long, the terminalexpanded artic- data from Hitchcock (1933), Silveus ulation ca 0.3 mm in dia. Pistillate (1933), and Correll and Johnston (1970) branches appressed or ascending, to 7 cm as well as our presentfindings. long, pedicels 1-7 (-13) mm long, the ter- Perennial aquatic, immersed,culms and minal expanded articulation 0.5-0.9 mm leaves long-streamingin river currents in dia. Staminate spikeletsovate or oblong, with only inflorescenceemergent, or in 6.5-11.0 mm long, 1.2-2.0 mm wide, gla- slow currentswith upper culms and leaves brous to pubescent or scaberulous; lemma emergent.Culms many,decumbent, genicu- and palea similar, thin, acute to short late, rooting at lower nodes (Fig. 4), caudate-acuminate. Anthers six, linear, stoloniform,to 3 m long (reported some- yellow, 3.2-7.0 mm long. Mature pistillate times 5 m by Silveus 1933) when im- spikelets 9.0-12.5 mm long, 1.2-1.8 mm mersed,1-2 m when partly emersed,basal wide, lemma and palea adnate along mar- sheathsyellowish or straw-colored.Ligules gins, somewhat thickened and leathery, usually dark basally, whitishdistally, 4-12 light brown,greenish, or basal half green- mm long, 2-5 mm wide, caudate-acuminate ish, distal half whitish,somewhat lustrous, or acuminate.Leaves linear, immersedones tapering gradually to terminal awn 9-35 softand flexible,to ca 1 m long, to 13 (-20) mm long and scabrous or hispidulous with mm wide (reportedto 25 mm wide by Sil- scattered prickle hairs, these slightly veus 1933), aerial leaves ratherstiff, taper- denser and longer at base of awn. Aborted ing to caudate apices. Panicles 16-31 cm pistillate spikelets 7.5-12.0 mm long, 0.7- 54 BULLETIN OF THE TORREY BOTANICAL CLUB [VOL. 105

1.2 (-1.5) mm wide. Caryopses (as grown zomes of Zizaniopsis miliacea (Miehx.) in cultivation) 4.3-7.6 mm long, 1.0-1.5 Doell & Aschers. Dore (letter to Terrell, mm wide, cylindrical,widest near middle 26 Nov. 1974) explained that some years and gradually taperingto slightlyrounded ago after he had requested plants of ends, only 1/2-3/4 as long as lemma and Zizania texana from a Texas correspon- palea, black, brown, or greenish, linear dent, he was sent rhizomes which grew scutellum1/2-3/4 as long as caryopsis. into Zizaniopsis miliacea. In this paper we use the commonname During the presentstudy Emery found "wildrice," following Correll and John- Zizaniopsis miliacca along banks of the ston (1970). We follow Dore (1969) in Saui Marcos River and at two sites im- recognizingas distinct species Z. aquatica mersed in the river, with streamingculms L. (southernwildrice) and Z. palustris L. alndleaves. One planltwas grownto matur- (northerlnwildrice). The former is con- ity from rhizomes. Emery found that centratedalong the Atlantic Coastal Plain Zizaniopsis miliacca may be distinguished westward to Louisiana, and extends into vegetatively from Zizania by its bluish southernNew England and westwardinto coloration, leaf anatomy, and large rhi- Wisconsin. The latter is in New England, zomes. Terrell & Robinson (1974) noted eastern Canada, and Great Lakes region differencesalso in the arrangementof the westwardinto Manitoba. Northernwildrice stellate cells in the leaf sheath, and after has long been known as an Indian food (it comparingZizania and Zizaniopsis in sev- usually has larger grains than southern eral importantreproductive and vegetative wildrice) and has recently been brought charactersconcluded that theybelonged in into cultivationin Minnesota and Canada separate subtribes. as a new crop. Anotherspecies, Z. latifolia Taxonomic comparisons of Z. texana (Griseb.) Turez. ex Stapf, is native to with otherZizania species are limitedhere easternAsia. to a tabular comparisonand brief discus- Little has been known previouslyabout sion, pending the completion of more the taxonomic status of Z. texana. Dore definitivestudies. We consider Z. texana (1969) called it a "dubious species" and a good species as its differsin several char- suggested that its underground parts acters (Table 1). We grew Z. texana side- might have been confused with the rhi- by-side with Z. aquatica and Z. palnstris Table 1. Comparison of three American taxa of Zizania.*

palustris var. aquatica var. texana palustris aquatica

Duration Perennial Annual Annual Plant height (m) 1-2 1-2 2-4.3 Habit Immersed, prostrate, Usually 25-75% Usually 70% or varying to erect and emergent more emergent mostly emergent Leaf width (mm) 7-13(-20) 4-14 Usually 10-53 Pistillate infl.brchs. Appressed Appressed Wide-spreading (at maturity) Ligule (upper) shape Caudate-acuminate Rounded, truncate, Rounded, truncate or acuminate or somewhat or somewhat acuminate acuminate Spikelet length (mm) 9.5-12.5 10-20 7.5-21 width (mm) 1.2-1.7 1.7-2.1 1.0-1.8 Lemma, palea: texture Somewhat leathery Leathery Papery Margins attached Rather tightly Tightly Loosely, sometimes separating Prickle hairs Scattered In lines Scattered Caryopsis length % 50-70 70-90 80-90 Spikelet length

* Excluding Z. aquatica var. brevis (see text) and Z. palustris var. interior(Fassett) Dore (Z. aquatica var. interiorFassett). Latter may be hybrid of Z. aquatica and Z. palustris. 1978] TERRELL, EMERY AND BEATY: TEXAS WILDRICE 55 in a greenhousetank at Beltsville, Mary- house potting soil. They were then placed land, and in an outdoor sluice at San in a 1 x 3 m tank of tap water and were Marcos, Texas. In cultivation Z. texana maintained with a few em of water over changed from a prostrate,immersed plant the soil surface in the pots. The water in to an erect, emergentone, but significant the tank was regulated at a constanttem- differenceswere maintained in spikelet perature of ea 23 C and was kept eirculat- and infloreseencecharacters, leaf width, ing (but not aerated) by an electricpump. and plant height. Water was replaced at monthly or bi- The lemmas and paleas of Z. texana monthlyintervals. bear scattered prickle hairs like Z. aqta- By December 1973, only one of the tica, whereas Z. paltstris has these hairs three plants had survived. This plant, in- in lines. The textures of the lemmas and stead of growing immersedas in nature, paleas in Z. texana are more or less inter- produced several erect, aerial culms up to mediate to those in Z. aqutatica and Z. 1 m high. The plant floweredabundantly palutstris (Table 1). In Z. texana spikelets from January 1974 through the summer fromcultivated plants in Texas and Mary- of 1974, and resembled the aerial culms land (differentclones) the mature car- shown in Fig,. 1, but was somewhat less yopses are only 50-70% as long as the robust. The plant was eventually divided lemma and palea; in Z. aqutatica and Z. into four. In autumn-winter,1974, these palitstris the caryopses occupy nearly all plants were attacked by two-spottedmites of the spikelet. The panicle of Z. texana (Tetranychus itrticae Koch) and were con- is rather similar to that of Z. palitstris in siderablyweakened. By January,1975, the having,appressed pistillate branches (vis- plants were dead. It is suspected that the ible in Fig. 1), rather than the long, mites were not entirely responsible for widely-spreading ones of Z. aqutatica. their demise; environmentalfactors may Zizania texana is also similar to Z. palits- not have been favorable for growth. tris in having narrow leaves and relatively During 1974 about 80 seeds were ob- low stature. Zizania texana is the only tained from self-pollinationof the plants perennial American species, but it remains in the greenhouse.These seeds appeared to to be determinedhow stronglyperenniality be of normalsize comparedto othersin the is influencedby the warm, more or less herbarium of the Patuxent Wildlife Re- constant temperaturein the San Marcos search Center, Laurel, Maryland. Some River. Zizania texana is somewhatsimilar seeds germinated,but consistentlyfailed vegetativelyto Z. aqutatica var. brevisFas- to survive after reaching7a few cm length. sett, an endemic of the St. Laurence estu- A few seedlings grown in San Marcos ary in Quebec, but spikelet and inflores- River water also died. Further attempts cence charactersof var. brevis are similar were made in 1975 and 1976 to grow Z. to these of Z. aqutatica var. aquatica. The texana in the greenhousetank at Beltsville, chromosomenumber in Z. texana is n = 15 but even in the presence of supplemental or 2n = 30 (Brown 1950), which is the light the seedlings died. We concluded same as that reported for Z. aqtuatica and that Z. texana needed special requirements Z. palustris. not adequately met at Beltsville; seedlings Emery has obtaineddata (unpublished) of Z. aquatica and Z. palutstris were grown on amino acid contentin Z. texana grains. to maturityunder these same conditions. It will be interesting to compare these In 1975 Emery moved four clones of data when published with those already Z. texana from its river habitat to a con- known for protein and lysine in Z. aquta- stant temperature, artesian, sprino-fed tica, Z. palustris, and Z. latifolia (Terrell sluice on the campus of Southwest Texas and Wiser 1975) and for other amino State Universityin San Marcos, where it acids in Z. palustris (as Z. aqutatica) by was possible to regulate both the velocity Oelke (1976). and depth of the water. The four clones Observations in cultivation. Three produced vigorous growth and abundant small clumps of Z. texana collected from foliage. Their growth form was dramat- the San Marcos River were brouoht to ically altered. The decumbent culms and Beltsville, Maryland by Terrell in Sep- submerged leaves characteristic of the tember1973, wherethey were transplanted river clones chanoed to erect culms with into larogeplastic pots containingfgreen- emerg,ent aerial leaves. Iinfloreseences 56 BULLETIN OF THE TORREY BOTANICAL CLUB [VOL. 105 formed, and cross fertilization of the icant vegetative spread from existing numerousflorets produced morethan 1,500 clones. seeds during the summerof 1975. As with The wildriee is particularlyvulnerable other wildrice species, freshly harvested to chemical changes in its aquatic milieu. seeds appeared to have an extended dor- An additional threat is the ever-present mant period. When seeds were placed in possibilityof accidental pollution by run- spring water and refrigeratedat 3 C, 105 off of locally-applied herbicides or pesti- days were adequate to break the dormancy. cides. Germination varied from 60-100%. The The best means of preserving the dormancy of Texas wildrice appeared to species is by preservingthe habitat intact be related in part to the permeabilityof and undisturbed.Education of the public the pericarp. Germination (usually less may help in this regard through talks, than 50%) may be obtained soon after newspaperreports, and articles such as the harvest by either puncture or scraping of one by Beaty (1975). We would discourage the pericarp away from the embryo (cf. the casual collectingof Z. texana by botan- Simpson 1966, and Woods and Gutek ists and others. 1974). A partial management alternative is Seeds were germinatedin petri dishes transplantationto other localities. Clones filled with tap water. The water was transplantedto Salado Creek,Bell County, changed daily. Seven to ten days after central Texas, have so far been successful. germinationthe seedlingswere transferred Emery's program of cultivation in a to pots containing river gravel. The pots spring-fed sluice is intended to permit were kept immerseda few cm below the relocation without encroaching on native water surface and care was taken to pre- populations. More than 100 clones of nur- vent currentsthat would disturb the seed- sery-grownwildrice were transplanted in lings. By the end of August, 1976, about 1976 to locations in central Texas. Trans- 500 sexual clones of Z. texana had been plantings to Spring Lake were eaten by culturedin this way. the introducedmammal,, Nutria, (Myocas- Aspects of conservation. Zizania tex- tor coyputs (Molina). It is hoped that ana was proposed as an endangeredspecies transplantingselsewhere, especially to bar- in the list published in the Federal Regis- ren sections of the San Marcos River, can ter (U.S. Fish and Wildlife Service 1976). ultimately succeed. In the introduction We believe this designationto be a realistic effort,we are faced with some of the same one. The location of Z. texana within the pressurescausing the decline of the native city limitsof San Marcos has made protec- populations and with the very restricted tion difficult.Emery (1967) in discussing physiological and ecological requirements the decline of the wildrice mentionedsome of Texas wildrice. Data now being accum- assessmentof disturbingfactors: (1) the regular mow- ulated may lead to a better the ing of aquatic vegetation in Spring Lake the vital requirementsof species. to render the lake more attractiveto tour- Cited ists allows floatingmasses of cut vegetation Literature to move downriverand damage or break BEATY, H. E. 1972. Zizania teXana Hitclic. offthe exsertedinfloreseences of the wild- (Texas wvildrice): A rare alid elidangered rice; this interfereswith pollination and species. 31 p. Ulnpublished. Baylor Univ., workers Waco, Texas. reproduction by seed, (2) city ice. Texas Hor- the river 1975. Texas wildr periodically plough or harrow ticulturist2: 9-11. bottomin accessible locations to rid it of BROWN, W. V. 1950. A cytological studly of clogging vegetation, (3) two commercial solmieTexas Gramiiiieae. Bull. Torrey Bot. enterprises selling exotic aquatic plants Club 77: 63-76. for home aquaria disturb the river and CORRELL, D. S., alnd M. C. JOHNSTON. 1970. lake vegetation, (4) raw sewage is dis- Manual of the Vascular Plants of Texas. charged into the river wheneverthe capac- Texas Research Foulndatioln,Relilier, Texas. ity of the city's sewage systemis exceeded. 1881 pp. Emery (1977) reported that ten years DORE, W. G. 1969. Wild-Rice. Caln. Dept. Agric. later the impact of these factors had sig- Publ. 1393. 84 pp. nificantlyabated, but there had not been EMERY, W. H. P. 1967. The decline aiid thrent- any reproductionfrom seed or any signif- elled extinction of Texas (Zizania 1978] TERRELL, EAMERY AND BEATY: TEXAS WILDRICE 57

texana Hitche.). Southli. Natur alist 12: , alnd H. ROBINSON. 1974. Luziolilnae, 203-204. a new subtribe of oryzoid grasses. Bull. 1977. Current status of Texas wild Torrey Bot. Club 101: 235-245. rice. Southiw. Naturalist 22: 393-394. TEXAS WATER DEVELOPMENT BOARD. 1968. Recol- HITCHCOCK, A. S. 1933. New species alnd nlew naissance of the chemiiical qualities of the names of grasses from Texas. Jour. Wash. surface waters of the Guadalupe River Acad. Sci. 23: 449-456. Basin, Texas. Report 88. Austin, Texas. OELKE, E. A. 1976. Amino acid contelntin wild U.S. DEPARTMENT OF INTERIOR. 1967-71. Water rice (Zizania aquatica L.) grain. Agron. resource data for Texas. Part 1. Surface Jour. 68: 146-148. water records. U.S. Geol. Surv., Federal SILVEUS, W. A. 1933. Texas Grasses. The Clegg Bldg., Austin, Texas. Co., San Antonio, Texas. 782 pp. U.S. FISH AND WILDLIFE SERVICE. 1976. [Pro- SIMPSON, G. M. 1966. A study of germination posed rules]. Proposed elndalngered status in the seed of wild rice (Zizania aq1tatica). for somiie 1700 U.S. vascular planit taxa. Caniad. Jour. Bot. 44 (1): 1-9. Federal Register 41 (117, IV) [June 16]: TERRELL, E. E., andl W. J. WISER. 1975. Proteini 24523-24572. and lysine contents in grains of three WOODs, D. L., and L. H. GUTEK. 1974. Germiniat- species of wild-rice (Zizania; Gr-amineae). ing wild rice. Canad. Jour. P1. Sci. 54: Bot. Gaz. 136: 312-316. 423-424.