Red firespike is a vigorous ornamental shrub growing to ≈1.8 m in height ( Daniel and McDade, 1995 ). Red firespike has an upright growth habit and is commonly cultivated as an ornamental plant in the garden due to its attractive tubular red flowers
Amir Rezazadeh, Richard L. Harkess, and Guihong Bi
Fulya Baysal-Gurel and Ravi Bika
persistent ornamental shrub; however, it can be severely affected by powdery mildew caused by Podosphaera physocarpi ( Baysal-Gurel et al., 2020 ; Zlesak, 2012 ). The fungus is highly specialized and forms a close association with ninebark, and a condition
He Li and Donglin Zhang
showy flowers. The variations in flower shape and color, leaf shape and size, and habit have made mountain laurel a valuable ornamental shrub in gardens and landscapes ( Jaynes, 1988 ). More than 100 mountain laurel cultivars have been released through
He Li, Matthew Chappell, and Donglin Zhang
outstanding flowering native species ( Dirr, 2009 ; Jaynes, 1988 ). Its attractive, lustrous green foliage; showy inflorescences; and variations in morphological traits have made mountain laurel a valuable ornamental shrub in the nursery and landscape
Erin Agro and Youbin Zheng
ornamental shrubs ( Fig. 9 ). However, Hibiscus had visual symptoms of a N deficiency with leaf yellowing observed in CRF treatments of 0.05 to 0.65 kg·m −3 N and Cornus ’ growth was severely stunted at 0.05 and 0.35 kg·m −3 N. This suggests that leaf N
Qiang Liu, Youping Sun, James Altland, and Genhua Niu
). Tatarian dogwood is a popular ornamental shrub with white fruits, creamy-white flowers, and red stems in fall through late winter ( Dirr, 2009 ). It is widely used in residential landscape, public parks, and botanical gardens. The morphological and
Leiah M. Butler, William F. Hayslett, and Robert Harrison
A 24-month experiment was conducted to study the effects of shading levels on the foliage color changes in Fire Power Nandinas. This popular ornamental shrub is the dwarf form of the Heavenly Bamboo, Nandina domestica. It originated in New Zealand, and has vivid green leaf color in the spring and summer months that changes to a fluorescent red as winter approaches. In this experiment light was limited by covering the plots with black woven shadecloth of 43% and 78% shade, while allowing the control plots to receive full sunlight. Fifteen shrubs from each plot were randomly selected and 10 leaves per plant in each treatment were taken at 28-day intervals. The leaf color was recorded using a camera attached to a microscope. The results from this study indicate that changes in leaf color may be affected by the change of the seasons. The level of light/shade that the plants receive may also affect leaf color. The control group turned a bright fluorescent red, the 43% shade turned a deep red, and the 78% shade remained a deep green with few leaves turning red. Based on the different hues observed, this research indicates that limiting light has a direct effect on leaf color in this species. The correlation between the amount of sunlight received and the season of the year are the two factors that determine the degree of color change in this ornamental shrub.
Helen T. Kraus, Stuart L. Warren, and Charles E. Anderson
Five ratios of NH4+: NO3-(100:0, 75:25, 50:50, 25:75, and 0:100) were evaluated for impact on growth of Cotoneaster dammeri Schneid. `Skogholm' (cotoneaster), a woody ornamental shrub, and Rudbeckia fulgida Ait. `Goldsturm' (rudbeckia), an herbaceous perennial. Nitrate alone decreased dry weight and leaf area of cotoneaster and rudbeckia compared with mixtures of NH4+ and NO3- and NH4+ alone. Additionally, NO3- alone suppressed accumulation of cationic nutrients and N in cotoneaster, while mixes of NH4+ and NO3- enhanced accumulation of nutrients in roots and shoots of rudbeckia compared with solutions containing either NH4+ or NO3- alone. The steles of roots of cotoneaster and rudbeckia contained more secondary xylem with larger tracheary elements with a mix of 25 NH4+: 75 NO3- than with NO3- alone.
Yulia A. Kuzovkina, Michael Dodge, and Irina V. Belyaeva
Salix gracilistyla Miq., japanese pussy willow or rosegold willow, is an ornamental shrub commonly cultivated for its prominent display of catkins in early spring. Verification of stocks of willows in the North American landscape nursery trade revealed that another name—Salix chaenomeloides Kimura—is associated frequently with plants similar to S. gracilistyla. Morphological analyses conducted during this study have shown that the S. chaenomeloides binomial is misapplied often to S. gracilistyla, its cultivars and hybrids. A comparison of the diagnostic characters of S. gracilistyla and S. chaenomeloides is presented to explain the differences between these taxa and to promote the adoption of the correct names. Five cultivars of S. gracilistyla valued for their early spring catkin displays, variegated foliage, and pendulous habits, and two cultivars of a hybrid origin are summarized. Also, two new ornamental cultivars called Salix ‘Winter Glory’ and Salix ‘Rabbit’s Foot’ are described.
Rolston St. Hilaire, Carlos A. Fierro Berwart, and Carlos A. Pérez-Muñoz
Mussaendas (Mussaenda spp.) are ornamental shrubs, and some cultivars are difficult to root. This study was conducted to explore how adventitious roots initiate and develop in the cultivar Rosea and to determine if anatomical events are associated with difficulty in rooting stem cuttings. Stem cuttings were treated with 5, 10, 15 mmol IBA, or distilled water, and sampled every 2 days over 26 days to observe adventitious root formation and development. Adventitious roots initiated from phloem parenchyma cells. Cuttings treated with 15 mmol IBA had a mean of 18 root primordia per basal 1 cm of cutting after 10 days. Primordia were absent in nontreated cuttings at 10 days. These results suggest that nontreated cuttings are difficult to root because few primordia are produced. Chemical name used: 1H-indole-3-butyric acid (IBA).