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ISSN : 1225-5009(Print)
ISSN : 2287-772X(Online)
Flower Research Journal Vol.23 No.4 pp.276-280

A New Hibiscus cultivar ‘Woolred’ with Vigorous Growth and Unique Flower Shape Through Interspecific Hybridization

Ho-Chul Kang1, Yoo-Mi Ha2*, Kwang-Ho Kim1
1Department of Landscape Architecture, Gyeongnam National University of Science and Technology, Jinju 660-758, Korea
2Department of Landscape Architecture, Sungkyunkwan University, Suwon 440-743, Korea

Corresponding author: Yoo-Mi Ha Tel: +82-31-290-7851
September 8, 2015 November 19, 2015 December 4, 2015


A new Hibiscus cultivar ‘Woolred’ having vigorous growth, uniform plant habit, upright, compact branches, and unique flower shape was developed through interspecific crosses between H. sinosyriacus ‘Seobong’ (♀) and H. syriacus ‘Samchully’ (♂). Hibiscus breeding program was initiated in 2002 and Hibiscus × ‘Woolred’ was preliminarily selected as ‘R-161’ in 2004 due to its vigorous growth and stable flower quality with rich pink flower. The selected line was further evaluated for different growth characteristics such as leaf shape, leaf size, flowering characteristics, and tested for distinctness, homogeneity, and stability during 2007-2009. The new cultivar ‘Woolred’ had violet pink color flower (RHS N74C) with red eye spot, medium in size having fan petals. The size of flower was 11.5 cm and size of red eye was 3.2 cm. Leaves were 7.7 cm long and 4.2 cm wide. After the plant characteristics evaluation for 3 years (2007 ~ 2009), it was registered as a cultivar ‘Woolred’ (3702, No. of plant variety protection rights) in 2011. This newly developed cultivar ‘Woolred’ having vigorous growth and unique flower shape can be used as specimen plant in landscape.


    Gyeongnam National University of Science and Technology


    In ornamentals, interspecific breeding is considered to be the most important source of genetic variation. The introgression of genes may be part of a breeding program towards disease resistance, better growth vigor, winter hardiness or morphological alteration in general. Both sexual and asexual hybridization, by pollination and protoplast fusion respectively, are fit to induce the desired introgression into the acceptor species. However, the number of possible barriers is very high (Eeckhaut et al. 2006). The creation of interspecific hybrids, along with chromosome doubling technology, offers extended opportunities for ornamental breeders (Van Tuyl and Kim 2003), as demonstrated in many genera (Kobayashi et al. 2004; Sujatha and Prabakaran 2003; Van Huylenbroeck et al. 2004). Interspecific and even intersubgeneric hybridizations are highly interesting to combine desired traits from genetically distinct genotypes (Van Huylenbroeck and Van Laere 2008; Van Tuyl 1997). Attempts to create interspecific hybrids between H. syriacus and H. rosa-sinensis, especially to introduce new flower colors and forms, were not successful so far (Paek et al. 1989; Yu et al. 1976). However, some interspecific breeding work involving more tropical species of Hibiscus is published (Kuwada 1964; Tachibana 1958).

    Geographically, Hibiscus is mainly distributed in tropical and subtropical zones, with some species extending into the temperate regions of the world like; H. syriacus L. (althea or rose of Sharon) and H. sinosyriacus Bailey (Bates 1965). The similarity in natural distribution pattern of these species is an indication of a similar tolerance to environmental factors (Bates 1965). Among them, H. syriacus, a deciduous shrub with more or less distinctly trilobate leaves, is the most popular one. Breeding work is mainly done in this species. The color of the solitary flowers in the axils on the young wood varies from white, light pink or red to purple and blue, generally with a large crimson splash at the base of the petals. Single, semi-double and double blooms are known (Kim and Lee 1991; Yu and Yeam 1987). Flowering time is from the end of July till the first part of October (Bean 1973; Kim and Lee 1991; Krüssmann 1962). Basic chromosome number of H. syriacus is x = 20 and most cultivars are tetraploid, 2n = 4x = 80 (Skovsted 1941). H. sinosyriacus, 2n = 4x = 80 (Skovsted 1941), has broader leaves compared to H. syriacus. The leaves have short triangular lobes and the involucratal bracts outside the calyx are as long as the calyx or even longer (Bates 1965).

    In this study, at temps were made to develop new Hibiscus cultivars with vigorous growth, upright, compact branches, and unique flower shape through interspecific hybridization between H. sinosyriacus and H. syriacus. More specific, the aim was to introgress increased growth vigor into H. syriacus by interspecific hybridization with H. sinosyriacus.

    Description and Performance


    The breeding program which produced Hibiscus hybrid ‘Woolred’ extended over a period of some 8 years. The objective of the breeding program was to develop new Hibiscus cultivars with vigorous growth and unique flower shape through interspecific hybridization between H. syriacus and H. sinosyriacus.

    The new Hibiscus plant developed after cross-pollination between H. sinosyriacus ‘Seobong’ introduced from Belgium, as the female or seed parent and H. syriacus ‘Samchully’ (Plant patent number 1481) as the male, or pollen parent. For the cross H. sinosyriacus ‘Seobong’ × H. syriacus ‘Samchully’, in total 50 flowers were pollinated. The crosses resulted in 32 fruits (64.0% successful pollinations) which contained on average 4.5 seeds. Of the obtained seedlings 115 could be planted in the greenhouse. 87 F1 seedlings of H. sinosyriacus ‘Seobong’ × H. syriacus ‘Samchully’ transplanted in the field and then flowered in 2003. The new Hibiscus hybrid ‘R-161’ was discovered and selected in August, 2004 as a vigorous plant with in the progeny of the stated cross-pollination in anoutdoor nursery environment in the Research Institute of Rose of Sharon and Tiger Lily, Chonan, Korea. Asexual reproduction of the new Hibiscus hybrid ‘R-161’ by hardwood grafting and softwood cuttings in a controlled greenhouse environment since the spring of 2004 has shown that the unique features of this new Hibiscus plant are stable and reproduced true to type in successive generations of asexual reproduction (Fig. 1). After the plant characteristics evaluation such as growth characteristics, leaf shape, leaf size, flower characteristics, and flowering for 3 years (2007 ~ 2009), it was named as ‘Woolred’ in 2010. The characteristics were evaluated based on the manual for agricultural investigation and guidelines for the conduct of tests for distinctness, uniformity and stability for Hibiscus (UPOV 2005).


    Plants of ‘Woolred’ had vigorous growth, and upright branches with abundant production of violet-pink (N74C) (Royal Horticultural Society Flower Council of Holland 2001) flowers of moderate size (10 ~ 11 cm) with a violet-pink, red eye spot at the base of each petal, which was visible from a distance (Fig. 2).

    The ‘Woolred’ was a vigorous and tall sized plant with upright branches. 5-year-old plant of ‘Woolred’ was 260 cm in height and 180 cm in crown width, and 1-year-old grafted plant was 75 cm in height and 50 cm in crown width (Table 1). ‘Woolred’ was more vigorous compared to H. sinosyriacus. Fig. 2 showed the overall appearance of the new Hibiscus, showing the colors as true as it was reasonably possible to obtain in colored reproductions of this type. Colors in the photographs might differ slightly from the color values cited in the detailed botanical description which accurately described the colors of the new Hibiscus × ‘Woolred’ (Fig. 2). This cultivar was very fertile with abundant seed pods produced from insect pollination.

    Leaves were alternate and oval shape (Table 2). The leaf apex was acute, and the base of the leaf was shallowly acute. Leaf margins were irregularly dentate. The leaves were 7.7 cm long and 4.2 cm wide. They were medium to darkgreen in color. The intensity of the green coloring depended upon the nitrogen nutrition of the plant. The new ‘Woolred’ in well grown plants attained a diameter of leaf shoulder of 2.3 cm and a petiole of 1.7 cm. The flower diameter of Hibiscus × ‘Woolred’ was 10.5 ~ 11.5 cm and similarly as compared with contrastive cultivar, ‘Samchully’. The corolla was composed of five slightly fan type of petals, 6.3 cm long by 4.5 cm at the widest point. The petals were violet pink (N74C) (Table 3, 4). The red eye spot was slightly darker red (53A) in color for 3.2 cm (Table 3, 4). A stout staminal column protruded from the central petal attachment that measured 3.3 cm long (Table 5). It beared numerous short-stalked yellow stamens along the basal two-thirds then became bare for about 1.2 cm before terminating into five stigmatic branches, each terminating in a capitate stigmatic lobe. In color, the column shaded from light yellow (NN155C), at the base to cream (154D), at the stigmatic lobes. The pistil protruded from the tip of the anther column before separating into five styles, each 0.5 cm long (Table 5).

    Upon anthesis in the early morning, the flower petals reflexed, then gradually returned to nearly right angles to the central axis and remained thus for the life of the flower (Table 4, 6). Hibiscus ‘Woolred’ started to flower each year in early July and continued for about four months, depending upon environmental conditions. The flowering of ‘Woolred’ initiated on July 12 and then total blooming duration was 86 days in Chonan, Korea. The plants then produced sporadic flowering until frost (Table 6).

    The stiff, upright main stems of H. × ‘Woolred’ apparently were derived from H. syriacus. It seemed to be increased for vigorous growth into H. syriacus by interspecific hybridization with H. sinosyriacus. The flower color in Hibiscus × ‘Woolred’ was intermediate between the flower colors of H. sinosyriacus ‘Seobong’ and H. syriacus ‘Samchully’. In pose, the flowers of H. × ‘Woolred’ somewhat resembled those of the species H. sinosyriacus in that the flowers expanded their petals widely.

    The oval three-lobed leaves of Hibiscus × ‘Woolred’ also resembled those of H. sinosyriacus in shape. H. sinosyriacus was allied to H. syriacus, but had broader leaves, with three short triangular lobes (Bates 1965; Bean 1973).

    Plants of the new Hibiscus were more vigorous than plants of the cultivar ‘Seobong’. Hibiscus × ‘Woolred’ differed primarily from plants of ‘Seobong’ in growth habit and flower size as plants of the new Hibiscus were more vigorous and had larger flowers than parent plants. ‘Woolred’ differed from plants of the female and male parents in leaf size and flower color as plants of the parents had smaller and lighter pinkcolored flowers.

    Notes for Production

    The new Hibiscus × ‘Woolred’ plant grows in well-drained soil. It easily grows in average and medium moisture in full sun to part shade. Best flowering occurs in full sun. It prefers moist, organically rich soils, but tolerates poor soils and some drought. It is very tolerant of summer heat and humidity. Prune to shape in spring. Pruning back to 2-3 buds in late winter may produce larger blooms. It is easily propagated by stem cuttings. May be grown from seed, but seedlings may not have the exact same flower color as the parent. Use a fertilizer that includes trace elements or iron, copper and boron. Perform all pruning in late winter, during the plant's dormant period.


    An application was filed for variety protection of ‘Woolred’ at the Korea Seed and Variety Service (Application no. 2010- 151) and the plant variety protection rights have been registered as grant number 3702 on August 30, 2011. Additional information or a list of nurseries propagating ‘Woolred’ is available on written request to Research Institute of Rose of Sharon and Tiger Lily (RIRS & TL), Chonan, Korea (e-mail: In addition, specimens of the releases have been deposited in the Research Institute of Rose of Sharon and Tiger Lily where it will be available for research purposes. The cultivar had been already released by RIRS & TL, Chonan, Korea and has been selling as commercial variety for domestic market.



    Pedigree diagram of a new bred F1 hybrid, ‘Woolred’.


    Flower and plant shape of female, male plant, and a new cultivar ‘Woolred’ by interspecific hybridization (2010).


    Growth characteristics of a new cultivar ‘Woolred’ by interspecific hybridization.

    zMean ± standard deviation (n = 5).

    Leaf characteristics of a new cultivar ‘Woolred’ by interspecific hybridization.

    zMean ± standard error (n = 10).

    Flower characteristics of a new cultivar ‘Woolred’ by interspecific hybridization.

    zUPOV TG/ (I-a: Single flower and not overlap, I-b: Single flower and slightly overlap: I-c: Single flower and overlap).
    yUPOV TG/ (I-type: Spatulate, II-type: Fan: III-type: Spoon).

    Flower size of a new cultivar ‘Woolred’ by interspecific hybridization.

    zMean ± standard error (n = 10).

    Characteristics of stamen and pistil of newly developed Hibiscus cultivar ‘Woolred’.

    zMean ± standard deviation (n=10).

    Flowering characteristics of a new cultivar ‘Woolred’ by interspecific hybridizationin 2014.

    zAll cultivars were cultivated in Cheonan-si, Chungcheongnam-do Province.


    1. Bates DM (1965) Notes on the cultivated Malvaceae , Baileya, Vol.13 ; pp.57-1301. Hibiscus.
    2. Bean WJ (1973) Trees and shrubs hardy in the British isles , John Murray, ; pp.121-155
    3. International Union for the Protection of New Varieties of Plants (UPOV) (2005) Guidelines for the conduct of tests for distinctness, uniformity and stability for Hibiscus , ; pp.1-28
    4. Kim JH , Lee KC (1991) Studies on the flower color variation in Hibiscus syriacus L. I. Spectral properties of fresh petals and flower color classification , J Korean Soc Hort Sci, Vol.32 ; pp.103-111
    5. Kobayashi N , Hagiwara J , Miyajima I , Facciuto G , Soto S , Mata D , Escandon A (2004) A new pot plant variety bred by interspecific crossing between Tecoma stans (L.) H.B.K. and T. garrocha Hieron , J Jpn Soc Hort Sci, Vol.73 ; pp.69-71
    6. Krüssmann G (1962) Handbuch der Laubgehölze. Band 2 , Paul Parey,
    7. Kuwada H (1964) The newly artificially raised amphidiploids plant named ‘Ai-Fuyo’ (Hibiscus muta-moscheutos), obtained from the progeny of H. mutabilis • H. moscheutos (Studies on interspecific and intergeneric hybridisation in Malvaceae VII) , Jpn J Breed, Vol.14 ; pp.27-32
    8. Paek KY , Hwang JK , Jong SK , Park SI (1989) Somatic hybridization by protoplast fusion in Hibiscus syriacus and Hibiscus rosachinensis , Korean J Breed, Vol.21 ; pp.95-102
    9. Royal Horticultural Society Flower Council of Holland (2001) RHS colour chart ,
    10. Skovsted A (1941) Chromosome numbers in the Malvaceae II. Comptesrendus des traveaux du laboratoire Carlsberg , Série Physiol, Vol.23 ; pp.195-242
    11. Sujatha M , Prabakaran J (2003) New ornamental Jatropha hybrids through interspecific hybridization , Genet Res and Crop Evol, Vol.50 ; pp.75-82
    12. Tachibana Y (1958) An interspecific hybrid of H. mutabilis L. and H. moscheutos L. (Studies on Hibiscus III) , J Hort Ass Jpn, Vol.27 ; pp.201-206
    13. Van Eeckhaut TK , Van Laere K , Riek De J , Van Huylenbroeck JM (2006) Overcoming interspecific barriers in ornamental plant breeding. Floriculture, ornamental and plant biotechnology: advances and topical issues , Global Science Books, ; pp.540-551
    14. Van Huylenbroeck JM , Van Laere K (2008) Breeding Strategies for Woody Ornamentals , ; pp.391-401
    15. Van Huylenbroeck JM , Van Laere K , Eeckhaut T , Van Bockstaele E (2004) Interspecific hybridization in flowering shrubs , Acta Hort, Vol.651 ; pp.55-62
    16. Van Tuyl JM , De Jeu MJ Sawhney VK , Shivanna KR (1997) Methods for overcoming interspecific crossing barriers , Pollen Biotechnology for Crop Production and Improvement, University Press, Cambridge Univ. Press, ; pp.273-292
    17. Van Tuyl JM , Kim B (2003) Interspecific hybridization and polyploidization in ornamental plant breeding , Acta Hort, Vol.612 ; pp.13-22
    18. Yu TY , Yeam DY (1987) Korean national flower, Hibiscus syriacus , Hakwon Co, ; pp.-424
    19. Yu TY , Yeam DY , Kim Y (1976) A study on the breeding of Hibiscus syriacus L. on hybridization among introduced tetraploids and H. rosa-sinensis , J Korean Soc Hort Sci, Vol.17 ; pp.107-112
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      Frequency : Quarterly
      Doi Prefix : 10.11623/frj.
      ISSN : 1225-5009 (Print) / 2287-772X (Online)
      Year of Launching : 1991
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