Chrysojasminum Odoratissimum: The King of Jasmines

Chrysojasminum odoratissimum, commonly known as the Chrysanthemum Jasmine or Yellow Jasmine, is a highly prized variety in the Oleaceae family. Revered as the “King of Jasmines” in northern regions and often regarded as the “Prince” in the jasmine family, this species stands out for its exceptional characteristics.

The Chrysanthemum Jasmine is one of only three double-petaled species in the Jasminum genus, setting it apart from its relatives. Compared to common domestic jasmine varieties, it boasts nearly twice the size, with impressive flower diameters reaching up to 4 cm. The multi-layered petals, coupled with deeper-colored, glossy leaves, make it a highly sought-after ornamental plant.

I. Basic Introduction

Chrysojasminum odoratissimum is an evergreen shrub that can sometimes take on a twining, liana-like form. Its branches are distinctly angular and glabrous (hairless). The leaves are pinnately compound, arranged alternately, and characterized by their small, leathery texture. Leaf shapes range from ovate to elliptical, with pointed apices, cuneate bases, and entire margins that curl under slightly.

The flowers are a striking yellow color, highly fragrant, and bloom in terminal cymes. The calyx lobes are triangular, while the fruit is nearly spherical. Native to the Mediterranean region and Asia Minor, this species can be observed on the south side of Changxing Forest. It is distinguishable from Forsythia by its short calyx lobes and stamens that protrude from the corolla tube.

II. Growth and Distribution

Chrysojasminum odoratissimum originates from the Madeira Islands in the Atlantic Ocean. This subtropical origin contributes to its preference for warm, humid climates. While native to this specific archipelago, it has been cultivated and naturalized in various parts of the world with suitable climates.

III. Morphology and Features

As an evergreen shrub or liana-like plant, Chrysojasminum odoratissimum can grow up to 3 meters in height. Its slender, angular branches may be slightly hairy and exhibit a climbing tendency. The leaves are oppositely arranged, broad ovate to elliptical in shape, and noteworthy for their glossy appearance, distinct venation, and slightly wrinkled surface. Short, upwardly curved petioles bear soft, short hairs.

Flowering occurs primarily from June to October, with some deciduous varieties blooming from November to March. The fragrant white flowers are borne in terminal or axillary cymes, typically containing 3-9 blooms, most commonly three to four. The corolla is white and exceptionally aromatic.

Fruit production is rare, usually resulting in single drupes, occasionally double. The young fruit starts pale green, transitioning to yellow-green and finally purple as it matures. At full maturity, the fruit is a flat, spherical drupe. It’s worth noting that while jasmine flowers are often pollinated, fertilization is uncommon, leading to infrequent seed production.

The leaves are simple and opposite, with papery blades that can be round, elliptical, ovate-elliptical, or obovate. They measure 4-12.5 cm in length and 2-7.5 cm in width. The leaf ends are typically rounded or blunt, sometimes with a slightly cordate base.

Venation consists of 4-6 pairs of lateral veins, slightly concave or raised on the upper surface and protruding on the lower surface. Fine veins are often distinct and slightly protruding. Tufted hairs are frequently present in the vein axils on the lower leaf surface.

The inflorescence is a terminal cyme, usually bearing 3 flowers, though single-flowered or up to 5-flowered cymes can occur. Peduncles measure 1-4.5 cm long and are covered with short, soft hairs. Bracts are minute and cone-shaped, 4-8 mm long.

Pedicels range from 0.3-2 cm in length. The calyx may be glabrous or sparsely covered with short, soft hairs, with linear lobes 5-7 mm long. The white corolla has a tube 0.7-1.5 cm long, with oblong to nearly round lobes 5-9 mm wide, rounded or blunt at the apex.

The mature fruit is spherical, approximately 1 cm in diameter, and purple-black in color.

IV. Cultivation Methods

1. Strategic Bud Removal: In East China, around the Grain Buds period (typically early June), new branches sprout and the season’s first buds appear. Due to relatively low temperatures, these early buds often develop poorly. To conserve plant energy, remove all first-batch flower buds before they develop fully. This practice stimulates more new shoot growth and promotes the development of higher-quality flower buds.
2. Regular Pinching: After one or two years of growth, Chrysojasminum odoratissimum often produces several long, non-flowering branches from the base. Regularly pinch out the growing tips of these branches, leaving the remaining part comparable in height to the main stem. Generally, remove the top of the branch, leaving 2-3 pairs of small leaves. This technique usually results in 4-8 new branches sprouting from the cut, which will then produce flower buds.
3. Strategic Water Management: When flower buds reach the size of green beans and the first flower shows white (approximately a week before full bloom), begin controlling water intake. This “dry tree promotes flower” method involves withholding water until the potting soil turns pale, cracks appear on the pot’s surface, and the plant’s tender leaves and flower buds begin to wilt slightly. At this point, resume thorough watering.
4. Appropriate Fertilization: Chrysojasminum odoratissimum benefits from frequent, light fertilization. When transitioning potted plants from indoors to outdoors, apply a 16% mature bean cake fertilizer solution every 5-7 days. As buds form and the first batch of flowers bloom, supplement with phosphorus-rich fertilizer. After the first flowering, switch to a 20%-25% mature bean cake liquid fertilizer.

V. Value and Applications

Chrysojasminum odoratissimum is primarily valued for its ornamental and aromatic qualities in garden design and landscaping. Its heat and drought resistance make it suitable for various applications, including:

• Courtyard plantings
• Hedge formations
• Roadside greening along highways
• General garden ornamentation

As a superior fragrant, evergreen shrub, it enjoys widespread popularity both domestically and internationally. Its versatility and appealing characteristics suggest broad application prospects in horticulture and landscape design.