Iris consists of ∼300 species, and many are very popular in the Northern Hemisphere (Boltenkov et al. 2020). Irises are valuable ornamental landscaping plants because of their unusual flower colors and patterns and plant performance. Iris plant performance can be affected by the leaf length and width. Additionally, the interactions between the flowers and leaves can impact the ornamental characteristics, thus becoming important breeding objectives. Iris lactea var. chinensis has a well-developed root system and tolerates salinity and drought conditions well. It is also widely used for landscaping because of its wide distribution and beautiful, colorful, and elegant flowers (Abalori et al. 2022; Meng et al. 2015). However, the leaves of I. lactea var. chinensis are excessively long and narrow; therefore, after flowering, the leaves tend to bend in all directions. In contrast, a new cultivar of I. lactea var. chinensis, ‘Niao Chao’, stays very upright throughout the green leaf stage and has a stronger sense of vertical space because of its wider leaf structure. Compared with I. lactea var. chinensis, ‘Niao Chao’ has wider leaves, a darker perianth color, a larger flower diameter, and an overall more upright plant shape. The new cultivar was selected from a natural population of I. lactea var. chinensis and registered as ‘Niao Chao’ in 2021.
Origin
In 2011, a plant with a different flower color and leaf type was observed in a natural population of I. lactea var. chinensis in the Anda prairie, Heilongjiang Province, China. The plant was established at the Northeast Forestry University nursery, Harbin, China. Clones were vegetatively propagated from 2012 to 2017 for evaluation; thereafter, field trials with I. lactea var. chinensis for further evaluation were performed from 2018 to 2021. It was during these final field trials that the plants consistently exhibited their stable flower characteristics and wider leaves. In 2021, the new cultivar was named Niao Chao and officially licensed by the American Iris Society with accession number 21-0392.
Description
Field performances of ‘Niao Chao’ and I. lactea var. chinensis were recorded in a research field at the Northeastern Forestry University nursery, Harbin, China, from 2018 to 2021. The research field was designed with a randomized complete block design with 20 plants per genotype and three replications. Thirty plants of ‘Niao Chao’ and I. lactea var. chinensis (10 of the 20 plants × 3 replicates) were randomly selected to record morphological characteristics during the blooming period. The data were analyzed using SPSS 22.0 software (Lenovo, Beijing, China) (Table 1). All color numbers mentioned are from the Royal Horticultural Society Color Chart.
Morphological traits of ‘Niao Chao’ and I. lactea var. chinensis.
‘Niao Chao’ has a magnificent color and broad leaves, with outer perianths almost spreading when in full bloom and the flowers covering the top of the plant. The flowers are larger and darker in color than those of I. lactea var. chinensis, and the overall plant shape is more upright after flowering (Table 1; Fig. 1). The ‘Niao Chao’ leaves (1.30 ± 0.05 cm) are significantly wider than those of I. lactea var. chinensis (0.82 ± 0.03 cm) (Table 1; Fig. 1A–D). The flower diameter (7.55 ± 0.19 cm), length and width of inner perianths (6.04 ± 0.03 cm and 1.74 ± 0.05 cm), length and width of outer perianths (6.02 ± 0.18 cm and 1.98 ± 0.07 cm), and style width (0.93 ± 0.16 cm) of ‘Niao Chao’ are significantly larger than those of I. lactea var. chinensis, but the ovary length (2.59 ± 0.10 cm) is significantly shorter than that of I. lactea var. chinensis (4.56 ± 0.28 cm) (Table 1, Fig. 1E–J). ‘Niao Chao’, similar to I. lactea var. chinensis, has one bract on a scape and usually has two flowers inside. The flower color of ‘Niao Chao’ is darker than that of I. lactea var. chinensis. The outer perianths of I. lactea var. chinensis are light blue violet (RHS 90D), the inner perianths are medium blue violet (RHS N88D), and the style arms are light blue violet (RHS 91B) (Fig. 1H–J). The outer perianths of ‘Niao Chao’ are almost flat when in full bloom, the base is white (RHS N155C) with purple markings, the outer margin is dark violet (RHS 90A), and the base is yellowish (RHS 8C). The ‘Niao Chao’ inner perianths are violet (RHS 86A), erect when in full bloom, and the style arms are violet (RHS N88B) (Fig. 1E–G). Compared with I. lactea var. chinensis, ‘Niao Chao’ remains upright even during the postflowering stage (Fig. 1B). ‘Niao Chao’ flowers are taller than the leaves during the flowering phase, whereas the flowers of the I. lactea var. chinensis are hidden within in the leaves (Fig. 1A and C). The flowering periods for ‘Niao Chao’ and I. lactea var. chinensis occur from 1 to 25 May and from 20 May to 10 Jun, respectively, and the fruiting periods occur from May to August and June to September, respectively. No pests or diseases were observed during the trials, and both plants have fragrance-free flowers.
Representative plants at the flower stage and fruit stage and flowers of ‘Niao Chao’ (A, B, E, F, G) and I. lactea var. chinensis (C, D, H, I, J).
Citation: HortScience 58, 1; 10.21273/HORTSCI17001-22
Representative plants at the flower stage and fruit stage and flowers of ‘Niao Chao’ (A, B, E, F, G) and I. lactea var. chinensis (C, D, H, I, J).
Citation: HortScience 58, 1; 10.21273/HORTSCI17001-22
Representative plants at the flower stage and fruit stage and flowers of ‘Niao Chao’ (A, B, E, F, G) and I. lactea var. chinensis (C, D, H, I, J).
Citation: HortScience 58, 1; 10.21273/HORTSCI17001-22
In summary, the new cultivar Niao Chao differs from I. lactea var. chinensis because of its wider leaves, darker perianth color, larger flower diameters, and overall more upright plant architecture. This new cultivar blooms earlier than I. lactea var. chinensis, which is an important factor for cold regions because it can compensate for the lack of spring herb flowers in the colder regions. Because the new cultivar flowers earlier, has wider leaves with excellent ornamental characteristics, and the remains upright after autumn flowering, it is an excellent and valuable addition to garden applications.
Recommendations
‘Niao Chao’ fares well under a wide range of soil conditions. It is recommended for planting in well-drained soils. It can be vegetatively propagated in either spring or autumn. Weed control should be provided during the growing season.
Habit and Application
‘Niao Chao’ can be successfully overwintered in an unprotected state in Harbin, China (hardiness zone 3; mean annual minimum temperature range: −40.0 to −34.5 °C) (Widrlechner 1997). ‘Niao Chao’ can also be used in flower planters and as groundcover plantings for horticulture and urban landscaping.
Availability
Information about plant material and research of ‘Niao Chao’ can be obtained from Dr. Ling Wang (E-mail: wanglinghlj@126.com) at the College of Landscape Architecture, Northeast Forestry University, Harbin, China.
References Cited
Abalori, TA, Cao, WX, Weobong, CAA, Li, W, Wang, SL & Deng, XX. 2022 Spatial vegetation patch patterns and their relation to environmental factors in the alpine grasslands of the Qilian mountains Sustainability. 14 11 6738 https://doi.org/10.3390/su14116738
Boltenkov, E, Artyukova, E, Kozyrenko, M, Erst, A & Trias-Blasi, A. 2020 Iris sanguinea is conspecific with I. sibirica (Iridaceae) according to morphology and plastid DNA sequence data PeerJ. 8 e10088 https://doi.org/10.7717/peerj.10088
Meng, YY, Wang, HX, Zhang, SH & Chen, JH. 2015 Suitability evaluation of plants in bioretention stormwater management measure China Water & Wastewater. 31 23 142 145
Widrlechner, MP 1997 Hardiness zones in China. (Color map - scale ca. 1:16,360,000.) https://www.ars.usda.gov/midwest-area/ames/plant-introduction-research/home/maps/page-2/. [accessed 15 Nov 2022]
