Flowering and Seed Yield in Three Species of Prairie

Julia L. Bohnen and Anne M. Hanchek1

Additional index words. ohiensis, Dalea purpurea, Spartina pectinata, native plants, establishment, flowering

Summary. Production of native seeds and seedlings for landscaping and res- toration is an expanding horticultural industry in , but seed yields of many species from wild stands are often small and vary widely in quality. Fig. 3. Total chlorophyll content (mg•liter–1) of winter squash (Cucurbita maxima Duch. cv. In this work, we document phenolog- Delica) treated with hot water at 50C for 0, 3, 6, 9, and 12 min and stored at 10 (A) and 20C ical development and seed yield in cul- (B) for 4, 8, and 12 weeks. tivated and prairie-grown plants for Tradescantia ohiensis Raf. (Ohio spi- which fruits will maintain good ap- storage life of Butternut squashes. Food derwort), Dalea purpurea Vent. (pur- pearance and less storage rots for up to Technol. 9:372–373. ple prairie clover), and Spartina pecti- 8 weeks, and thus can reach distant Klein, J.D. and S. Lurie. 1992. Heat treat- nata Link (prairie cordgrass) at the markets with better quality. ments for improved postharvest quality of Minnesota Landscape Arboretum. For horticultural crops. HortTechnology T. ohiensis, seed yield under cultiva- 2:316–320. tion was significantly greater than in Literature Cited the prairie both seasons, with 2.5 g of Lurie, S. and J.D. Klein. 1990. Heat treat- seed recovered per in 1993. Un- Abdel-Rahim, A.M. 1988. Postharvest fun- ments of ripening apples: Differential ef- der cultivation, seed yield of establish- gal diseases of some vegetables in Kuwait. fects on physiology and biochemistry. ed D. purpurea was triple that of the Arab J. Plant Protect. 6:83–87. Physiol. Plant. 78:181–186. prairie, yielding 34 seeds per inflores- Dabrowski, A., J. Galazka, and S. Zalewski. cence. S. pectinata grown under culti- Lurie, S. and J.D. Klein. 1992. Ripening vation from seedlings or rhizome di- 1989. Technological properties, nutritional characteristics of tomatoes stored at 12C value, and storage properties of new pump- visions produced seed in the first and and 2C following a prestorage heat treat- second seasons, respectively, while kin varieties. Acta Alimentaria Polonica ment. Sci. Hort. 51:55–64. 15:153–159. plants in the prairie remained vegeta- Navarro, R. 1992. Producción de Kabocha. tive. Two-year-old seedlings produced Flores, E. 1992. Aspectos generales del Taller sobre producción de hortalizas. 38 seeds per spike. Field cultivation of cultivo de la calabaza kabocha (Cucurbita Memorias. SARH, INIFAP, CIRNO, these native plant species resulted in maxima Duch) en la Costa de Hermosillo. CAECH. Hermosillo, Sonora, México. increased seed yield and improved Departemento de Agricultura y Ganaderia. growth, while allowing phenological Disertación de licenciatura, Universidad Pedrosa, J.F., V. W.D. Casali., S.S. Cheng., monitoring and the use of species- de Sonora. M.I. F. Chitarra, and V.D. de Carvalho. specific harvest practices. 1983. Changes in composition of squashes Francis, F.J. and C.L. Thomson. 1965. Op- and pumpkins during storage. Pesquisa timum storage conditions for Butternut Agropecuaria Brasileira 18:29–32. squash. Proc. Amer. Soc. Hort. Sci. 86:451– Department of Horticultural Science, University of Min- 456. Rath, G.C., D. Mishra and N.C. Nayak. nesota, St. Paul, MN 55108. 1990. A note on fungi causing rotting of Research conducted at the Minnesota Landscape Arbore- Hawthorne, B.T. 1988. Fungi causing stor- cucurbits in Orissa markets. Orissa J. Agr. tum, Chanhassen. Minnesota Agricultural Experiment age rots on fruits of Cucurbita spp. N.Z. J. Res. 3:161–162. Station publication number 21189, partially funded by Expt. Agr. 16:151–157. a grant from the Legislative Commission on Minnesota’s Resources. From a thesis submitted by J.L.B. in partial Schales, F.D. and F.M. Isenberg. 1963. The fulfillment of the requirements for a MS degree in horti- Hawthorne, B.T. 1989. Effects of cultural effect of curing and storage on chemical practices on the incidence of storage rots in culture. Our thanks to the Minnesota Native Wild- composition and taste acceptability of win- flower/Grass Producers Assn., the Minnesota Dept. of Cucurbita spp. N.Z. J. Crop Hort. Sci. ter squash. Proc. Amer. Soc. Hort. Sci. Agriculture, and to Arboretum volunteers Jo Nielsen, 17:49–54. Kathryn McFadden, and Sue Tracey. The cost of publish- 83:667–674. ing this paper was defrayed in part by the payment of page Holmes, A.D. 1951. Factors that affect the charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact.

HortTechnology ● July/Sept. 1994 4(3) 255 RESEARCH UPDATE

ncreasing demand for native spe- vested from remnant prairie (Bohnen, Fifteen nonflowering plants each cies for use in highway plantings, 1994). Growers noted that Spartina of T. ohiensis, D. purpurea, and S. Irestoration, and landscaping pectinata (prairie cordgrass), Dalea pectinata were transplanted from es- projects has spurred the growth of the purpurea (syn. Petalostemum purpur- tablished populations in the 20-year- native wildflower and grass seed indus- eum) (purple prairie clover), and Tra- old created Bennett/Johnson Prairie try. Raising native plants from seed descantia ohiensis (Ohio spiderwort) at the Minnesota Landscape Arbore- poses a challenge to growers who sup- (nomenclature follows Gleason and tum (lat. 44.52N, long. 93.37W) in ply locally collected and produced na- Cronquist, 1991) frequently produce early June 1992. Transplants were tive plants to an ever-increasing num- low seed yields, often with low ger- moved to a cultivated field plot on the ber of consumers. Seed yields of many minability as well. Arboretum grounds within 1 mile of species from wild stands are small, and We established field trials at the the prairie on the same day that they vary in quality. One option is to grow Minnesota Landscape Arboretum to were dug, and planted in single blocks plants for seed in cultivated stock plots, compare seed yield of Tradescantia of three × five plants spaced 30 cm on but we know little about the yield ohiensis, Dalea purpurea, and Spartina center. Additional individuals were potential of these plants under a cul- pectinata under cultivated field man- transplanted at the same time to ac- tural regime. Cornelius (1950) docu- agement vs. in a noncultivated man- count for losses during establishment. mented yield for selections of seven aged prairie. Another 15 undisturbed plants were species of native grasses in cultivation identified and marked in the Bennett/ and yield for the same species in prairie Methods and materials Johnson Prairie for comparison of seed remnants, but direct comparisons could Because native prairie plants are yields. All individuals of each species not be made because of the logistics not common horticultural crops, some that were taken or marked came from involved in cultivating several species, description of these three species is the same area. By using transplants, we and climatic differences from location necessary to understand their growth hoped to reduce potential differences to location. Other research that has and development. Tradescantia ohi- between and within treatments due to documented seed yield in prairie plants ensis, a member of the , population differences and to indi- generally has compared different man- bears straplike leaves alternately on a vidual plant size. agement regimes or natural distur- succulent stem, with many vegetative We added one additional popula- bances within a prairie (Coffin and shoots produced during the growing tion of Spartina pectinata seedlings to Lauenroth, 1992; Hartnett, 1991). season. The bloom period is extended the cultivated plot in June 1992 to Still, some producers of native by the presence of numerous buds in allow comparison the following year seeds are exploring the advantages of each inflorescence. As a monocot, the between second-season seedlings and growing stock in small plots for better, floral parts are in 3s, and a seed capsule second-season divisions. These seed- more-uniform yields (Minnesota Dept. may contain up to six pitted, gray lings were produced from seeds col- of Agr., 1993). Field cultivation of seeds, two per locule. Each blue flower lected on 10 Sept. 1991 in Polk Co., native plant species provides an oppor- is 2 to 3 cm across and lasts only a day, Minn., and germinated in the green- tunity to control inputs and competi- opening in the morning and shrivel- house in Dec. 1991. tion, and to use species-specific har- ling by early afternoon (Runkel and The establishment season (Sum- vest practices, making seed cleaning Roosa, 1989). mer 1992) was generally wet and cool, easier and resulting in higher seed pu- Dalea purpurea is a deep-rooted, and irrigation was used sparingly, as rity. Because conditions that prevail somewhat woody-stemmed member needed. A 10N–4.3P–8.3K inorganic during seed maturation influence seed of the Fabaceae, with finely divided granular fertilizer was applied to the dormancy and germination (Mayer and compound leaves often folded over at cultivated plot in early July 1992 at the –2 2 Poljakoff-Mayber, 1989), seed pro- the edge (Gleason and Cronquist, rate of 24.4 g•m (5 lb N/1000 ft ). duced in the environment of a culti- 1991). The flowers are clustered in The area was hand-weeded. In 1993, a vated field might have greater ger- tight rose-purple cylindrical inflores- black woven weed barrier was laid down minability than seed harvested from cences or spikes, with each spike flow- around D. purpurea and T. ohiensis the wild. However, a disadvantage to ering basipetally. Lateral spikes are plants to reduce weed growth. Be- the cultivation of native plants is the generally shorter than terminal spikes, cause of its rhizomatous growth habit, potential for loss of genetic diversity and tend to begin flowering after the the weed barrier could not be placed through inadvertent selection. terminals. around S. pectinata. The 1993 grow- Most native plant producers have Spartina pectinata is a warm-sea- ing season was also unusually wet and some acreage under cultivation, rang- son rhizomatous grass of wet prairies cool (Bohnen, 1994), and irrigation ing from 1 to 240 acres of forbs and/ that forms large clonal colonies (Runkel was not necessary. or grasses (Bohnen, 1994). However, and Roosa, 1989). The coarse, sharp- Ongoing management in the half of them continue to harvest from edged leaf blades turn yellow in au- Arboretum’s prairie consists of a con- remnant prairies for some of their tumn. The flowering stems of S. trolled burn every 2 or 3 years. The needs. When members of the Minne- pectinata may be 1 to 2 m tall, each prairie was not burned during the 1992 sota Native Wildflower/Grass Produc- bearing a stiff raceme with 10 to 20 season, but was burned thoroughly in ers Assn. and others were surveyed upright branches (Hitchcock, 1951). Apr. 1993. about production problems in gen- Each branch of the raceme is a spike Soil in the cultivated plot was eral, their responses raised several ques- consisting of many sessile one-flow- fine-textured, with high organic mat- tions concerning seed yield for three ered spikelets (Soil Conservation Ser- ter and a pH of 7.4. The soil in the species in particular that often are har- vice, 1968). Spartina, Tradescantia, and Dalea ar-

256 HortTechnology ● July/Sept. 1994 4(3) eas in the prairie was of medium tex- Anthesis began in both treatments oped. Therefore, actual mean yield ture, with high organic matter and a in early to mid-June. The bloom pe- during the second season under culti- pH of 6.4 to 6.7. riod lasted 16 weeks under cultivation vation was somewhere between 749 We measured seed yield both by and was longer than that of the prairie and 1827 seeds per plant over the number and weight. In addition, we in both years. In 1992, the mean num- entire season. documented number of inflorescences ber of open flowers peaked at the end Lower yield in the prairie plot per plant, plant height, and above- of August, probably delayed by trans- could be attributed to resource limita- ground dry weight as potential predic- plant shock (data not shown). In 1993, tion. In the prairie, where competition tors of yield. Dry weight of Trades- the mean number of open flowers un- between grasses and other forbs for cantia was sampled at the end of the der cultivation peaked at 25 per plant light, water, nutrients, and space is growing season by collecting every during the week of July 16 (Fig. 1). intense, T. ohiensis grew tall and did above-ground shoot from each plant The peak period of seed recovery be- not branch or produce basal shoots. in the study. Above-ground dry-weight gan 3 weeks later in 1993, lasting from Each flowering stem terminated in one samples for Spartina consisted of the 5 to 26 Aug. or at most two inflorescences. In 1993, three stems nearest the stake marking In 1993, the mean weight of total 27% of the plants had only vegetative each plant in the cultivated plot and in recovered seeds per plant based on shoots and did not develop flowering the prairie. We could not measure weekly sampling was significantly stems at all. The percentage of plants end-of-season dry weights for Dalea greater under cultivation than in the that flowered was greater in 1993 than because some leaf drop occurred be- prairie (Table 1). “Recovered seed” it was in 1992, perhaps due in part to fore the seed was ready to harvest. underestimates the actual yield be- the effect of the April burn. Con- Significant differences (α = 0.05) be- cause many seeds were dropped or versely, all plants under cultivation had tween cultivated and prairie treatments dispersed between the weekly sam- several flowering stems that frequently were identified using independent pling dates. Cultivated plants also branched and terminated in many sample t tests. showed a significantly greater total closely clustered inflorescences. T. potential flower number, as determined ohiensis under cultivation showed an Results and discussion by a comprehensive sampling of buds indeterminate growth habit, with new Tradescantia ohiensis. Plants and barren or pollinated flowers. In shoots and inflorescences developing in cultivation established quickly and 1993, in the prairie, the mean number until frost. Plants in the prairie began surpassed in size and flowering those of total potential flowers per plant was to senesce by early August. in the prairie treatment during the first 13, while under cultivation the mean Pollinator frequency appeared to year (Table 1). For both seasons, mean number of potential flowers per plant be an additional limiting factor in seed above-ground dry weight was signifi- was 1807. Potential seed number was production. During weekly sampling, cantly greater in cultivation than in the estimated by counting the number of pollinator activity was not noticed in prairie. Correspondingly, both mean expanded capsule locations. This fig- the prairie plot. However, honeybees number of shoots per plant and mean ure gives a high estimate of actual seed of the Order Hymenoptera, Super- number of inflorescences per plant were production because, in some instances, family Apoidea (J. Fetzer, personal greater each year under cultivation than the locular position had expanded, communication) were seen regularly in the prairie treatment. although the seed had not fully devel- in the cultivated plot. Flower flies of the Order Diptera, Family Syriphidae, Table 1. Developmental phenology, growth, and seed yield of Tradescantia ohiensis grown under also were seen daily. z cultivation vs. managed prairie . Daily anthesis seems to be weather-dependent, as shown by the 1992 1993 Item Cultivation Prairie Cultivation Prairie dips in the line graph for number of open flowers (Fig. 1). However, this Shoot emergence ---y 4 June 21 Apr. 14 May did not seem to influence the number Visible flower buds 16 June 23 June 2 June 10 June of seeds recovered under cultivation. First anthesis 23 June 29 June 10 June 20 June When harvesting in the prairie, timing First mature seed capsule 29 July 21 July 30 July 6 Aug. is critical because fewer flowers and End of bloom period 14 Oct. 29 July 1 Oct. 20 Aug. thus fewer seeds are produced. Infor- Shoot dry weight/ mation about number of seeds devel- plant (g) 30.3 ± 5.4* 1.0 ± 0.2 32.9 ± 7.7* 1.8 ± 0.4 oped, seed dispersal, and number of No. shoots/plant 10.5 ± 0.9* 2.0 ± 0.4 16.1 ± 2.2* 2.0 ± 0.3 open flowers might be used to predict No. inflorescences/ better an optimum time to harvest T. plant 22.1 ± 3.8* 0.3 ± 0.2 49.3 ± 10.4* 1.1 ± 0.2 ohiensis. Under cultivation, it may be No. recovered seeds/ possible to make two harvests using plant 114.1 ± 35.0* 0.3 ± 0.3 749.1 ± 207.3* 0.2 ± 0.2 this information. Seed weight/plant (g) ------2.5 ± 0.7* 0.001 ± 0.001 During these trials, we were able No. mature seeds to sweep dispersed seed up from the capsules/plant ------709.3 ± 158.8* 0.1 ± 0.1 weed barrier used around the plants. It No. buds and flowers ------1775.8 ± 379.6* 12.9 ± 2.7 might be possible to harvest in this zMean ± 1 SE, n = 15. manner from a small cultivated plot by yNo data. using a small shop vacuum. One pos- *Significantly greater than the same-year prairie mean at P ≤ 0.05. sible disadvantage to this technique is

HortTechnology ● July/Sept. 1994 4(3) 257 RESEARCH UPDATE

No seed was harvested from the culti- vated plot in 1992; only six of the 15 plants under cultivation developed in- florescences the first year. The trans- plants flowered later and consequently did not have fully matured seeds be- fore the plants were killed by a hard frost in November. In 1993, seed in the cultivated plot was harvested about 2.5 weeks after the prairie plot. Mean number of inflorescences initiated per plant in 1993 was not significantly different between treatments, but not all of these developed into flowering, seed- producing inflorescences. The total number of inflorescences that flow- ered in 1993 could only be docu- mented for the prairie treatment be- cause of the grazing damage in the cultivated treatment. However, aver- age inflorescence weight in the culti- vated plot was significantly greater than in the prairie. Seed weight and number per inflorescence also showed a 3-fold increase under cultivation. Even with rabbit damage to individuals, the cul- tivated plants still surpassed those of the prairie in total seed weight per plant. A larger percentage of the inflo- rescences initiated probably developed and flowered in the cultivated plot in response to greater resource availabil- ity. Pollinator frequency and efficiency also may have been factors supporting increased seed set. Honey bees and sweat bees (not identified to species) were seen on inflorescences of D. purpurea, and bumblebees also were noted in the cultivated area. Weevils, a chewing insect, were abundant on both Fig. 1. Number of open flowers and recovered seeds per plant per day for Tradescantia ohiensis stems and inflorescences in both treat- under cultivation; n = 15. Plants were sampled weekly from 1 June to 15 Oct. 1993. ments throughout the season, although no damage was noted. the potential for induction of second- Rhizoctonia in 1992, followed by deer Spartina pectinata. By Octo- ary dormancy in the seeds if left too and rabbit damage in 1993, reducing ber of the establishment year, trans- long on the black heat-absorbing weed the number of plants sampled in 1993 plants were producing tillers. By the barrier. A synthetic mulch with a light- to four in the cultivated plot and eight end of the 1993 season, mean dry colored upper surface might be more in the prairie. Because some plants shoot weight of the seedlings and divi- appropriate. under cultivation were only partially sions was significantly greater than in Dalea purpurea. This species, damaged by grazing, most of the Dalea the prairie treatment (Table 3). sensitive to disturbance, suffered some seed yield data were analyzed on a per- Spartina pectinata did not flower loss upon transplanting. For most in- inflorescence basis rather than whole in either the prairie or among the dividuals, the stems died back then plant. cultivated divisions in 1992. Seed pro- resprouted from latent buds near the In both seasons, flower spikes were duction for native warm-season grasses base. This regrowth resulted in plants visible in the prairie about a week during 1992 was poor overall in Min- with a spreading habit the first season. earlier than in the cultivated plot (Table nesota according to the native wild- In 1993, their growth habit was up- 2). Both the beginning and end of flower and grass producers, probably right and similar to that of the plants in anthesis occurred earlier in the prairie due to unseasonably cool tempera- the prairie treatment. Above-average treatment as well. Seed development tures. Even in more-seasonable years, rainfall contributed to an outbreak of in 1992 in the prairie took ≈15 weeks however, seed production by S. the fungal organisms Pythium and from first anthesis to seed maturity. pectinata is sporadic. However, flow-

258 HortTechnology ● July/Sept. 1994 4(3) Table 2. Developmental phenology, growth, and seed yield of Dalea purpurea grown under as many shoots per plant as in the z cultivation vs. managed prairie in 1993 . prairie. Improved yield under cultiva- tion for D. purpurea appeared to be Item Cultivation Prairie more a result of increased seed set per Spikes began to form 9 July 2 July inflorescence than increase in vegeta- First anthesis 6 Aug. 30 July tive growth. The S. pectinata trial sug- Last anthesis 1 Oct. 2 Sept. gests that yield can be increased in Hand-harvest of seedsy 26 Oct. 8 Oct. young stands. Equally important, cul- No. inflorescence initiated/plant 35.0 ± 7.2NS 29.1 ± 4.8 tivation may increase reliability of seed Weight/inflorescence (g) 0.36 ± 0.03* 0.25 ± 0.02 set, enabling native seed producers to Seed weight/inflorescence (g) 0.043 ± 0.005* 0.015 ± 0.003 keep pace with increasing demand. In No. seeds/inflorescence 33.5 ± 3.8* 11.5 ± 2.3 addition, because it reduces depen- Seed weight/plant (g) 0.49 ± 0.16x,* 0.22 ± 0.05 dence on prairie remnants, production No. seeds/plant 379.8 ± 119.5x,* 173.4 ± 47.3 of seed from stock plots may be a more z ecologically sound method of supply- Mean ± SE; cultivated n = 4, prairie n = 8. yBy this date, the florets had turned from green to gray and could be stripped easily from the spike. ing seed to both private and public xBased on incomplete sampling of the four individual plants. entities interested in environmentally NS,*Nonsignificant or significantly greater than the prairie mean at P ≤ 0.05. sound landscapes.

Table 3. Growth and seed yield in 1993 of Spartina pectinata grown under cultivation and in managed prairiez. Literature Cited Bohnen, J.L. 1994. Seed production and Item Prairie Cultivated divisions Cultivated seedlings germination of native prairie plants. MS Thesis, Univ. of Minnesota, St. Paul. Dry weight of three shoots (g) 8.5 ± 0.5y 22.5 ± 2.5x 24.0 ± 3.0y,NS No. inflorescences/plant None 4 10 Coffin, D.P. and W.K. Lauenroth. 1992. No. spikes/inflorescence None 16.1 ± 1.1 18.5 ± 1.0NS Spatial variability in seed production of the Weight/spike (g) None 0.11 ± 0.01 0.17 ± 0.02* perennial bunchgrass Bouteloua gracilis No. spikelets/spike None 46.2 ± 1.8 59.4 ± 2.5* (Gramineae). Amer. J. Bot. 79(3):347– 353. No. seeds/spike None 13.2 ± 2.2 38.3 ± 5.0* z Cornelius, D.R. 1950. Seed production of Mean ± 1 SE, n = 10, except as indicated. y native grasses under cultivation in Eastern Mean ± 1 SE, n = 13. x Mean ± 1 SE, n = 13. Kansas. Ecol. Monogr. 20(1):1–29. NS,* ≤ Nonsignificant or significantly greater than division mean at P 0.05. Gleason, H.A. and A. Cronquist. 1991. Manual of the vascular plants of the North- ering and seed production did occur in and divisions in cultivated treatments eastern and adjacent Canada. the seedlings in 1992, the same season could be attributed to either propaga- Van Nostrand, New York. they were planted. The divisions flow- tion or population differences. Fur- ered and produced seed in 1993, the ther research into the use of young Hartnett, D.C. 1991. Effects of fire in second season under cultivation. The stands for seed production is needed. tallgrass prairie on growth and reproduc- prairie plants did not flower either year Insect activity was not noticed on tion of prairie coneflower (Ratibida columnifera: Asteraceae). Amer. J. Bot. of this study. For a clonal plant such as S. pectinata during the growing sea- 78(3):429–435. this grass, various environmental fac- son, but a large number of seed bugs of tors may determine the ability of a the Order Hemiptera, Family Hitchcock, A.S. 1951. Manual of the grasses plant to flower and produce seed. Pro- Lygaeidae (J. Fetzer, personal com- of the United States. USDA, Washington ducers have observed that seed pro- munication), were discovered in dry- D.C. Publ. 200. duction occurs at the outside edge of a weight samples. Seed damage in S. Mayer, A.M. and A. Poljakoff-Mayber. 1989. Spartina population. Perhaps this grass, pectinata by chewing insects was noted The germination of seeds. Pergamon, New like a clump of old iris, needs division as a problem by one commercial pro- York. to rejuvenate the plant and promote ducer who has frequently found holes Minnesota Department of Agriculture. flowering. chewed through the inflorescence (A. 1993. An assessment of Minnesota’s native Mean number of inflorescences Wade, personal communication). wildflower and grass seed market. Market per plant was greater among the seed- Development and Promotion Division. lings than the divisions, but the mean Conclusions Rpt. 1993-600-1. St. Paul, Minn. number of spikes per inflorescence was Cultivation can significantly in- Runkel, S.T. and D.M. Roosa. 1989. Wild- not significantly different. However, crease seed yield for T. ohiensis and D. flowers of the tallgrass prairie: The upper other yield components, such as mean purpurea, and perhaps for S. pectinata. Midwest. Iowa State Univ. Press, Ames. weight per spike, mean spikelet num- Resource limitation in the prairie may ber per spike, and mean number of influence seed yield by limiting re- Soil Conservation Service. 1968. Key to the filled spikelets per spike, were signifi- sources available for reproductive as native perennial grasses: Midwest region cantly greater for seedlings than for well as vegetative efforts. This was east of the great plains. USDA SCG TP 151, Washington D.C. divisions. The differences in second- especially evident for T. ohiensis, which, year seed yield between the seedlings under cultivation, produced eight times

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