Abelia macrotera (Graebn. & Buchw.) Rehder

Landrein, S., Farjon, A. (2020). A monograph of Caprifoliaceae: Linnaeeae. Kew Bulletin 75: 1 doi:10.1007/s12225-018-9762-5

Morphology General Habit

Decumbent to large shrubs 100 – 150 cm tall

Morphology Branches

Young branchlets glabrous or densely short pilose with erect or curved hairs sometimes interspersed with short-stalked glandular hairs as well as a few long erect hairs, especially at the nodes

Morphology General Buds

Winter buds with several pairs of ciliate and pubescent perulae

Morphology Leaves

Leaves opposite but often whorled in 3s on reiteration shoots Leaves ovate to elliptic or oblong, 0.8 – 10 cm long, 6 – 40 mm wide, acute, acuminate to long caudate at apex, rounded to cuneate at base Leaf blade sparsely hairy to glabrous, but base of main vein usually densely covered with tufts of hairs abaxially Leaf margin entire, with irregular gland-tipped teeth, ciliate or with recurved margin

Morphology Leaves Petiole

Petioles short to 2 mm long

Morphology Reproductive morphology Flowers

Flowers axillary, solitary along new shoots and sometimes forming a terminal thyrse-like inflorescence Flowers held horizontally or pendulous

Morphology Reproductive morphology Inflorescences Peduncles

Peduncles short or elongated and thin with reduced leaf-like bracts

Morphology Reproductive morphology Flowers Epicalyx

Epicalyx of 4 prophylls, episepals triangular-lanceolate, glabrous or with a ciliate margin

Morphology Reproductive morphology Flowers Calyx

Calyx lobes 2, sepals ovate to oblong 5 – 10 mm long, 4 – 5 mm wide, obtuse or acute to acuminate at apex, cuneate to rounded at base Sepals often reddish with conspicuous venation, glabrous or with a ciliate margin

Morphology Reproductive morphology Flowers Corolla

Corolla lobes subequal, ovate, and slightly recurved Corolla tube 12 – 20 mm long, narrow and gradually expanding to the corolla mouth Base of corolla tube bulging ventrally with a nectary composed of dense glandular hairs, nectary to 2 mm in diameter Corolla bilabiate, 11 – 40 mm long, red-purple, throat and lower corolla lobes bearded and with strong orange markings, outside with short-stalked glandular hairs

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, didynamous and inserted within the corolla tube

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments adnate to lower part of corolla tube, hairy basally

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary lanceolate to ovate with or without a long terminal sterile neck, densely hispid to glabrescent Ovary longitudinally ribbed, ventrally compressed and widened along the fertile locule, 5 – 10 mm long

Morphology Reproductive morphology Flowers Gynoecium

Style glabrous to sparsely hairy at base, inserted to exserted from the corolla tube, stigmas capitate, white and papillose

Morphology Reproductive morphology Fruits

Fruit an achene with persistent, slightly accrescent and spreading sepals Achenes 1-seeded, to 10 mm long, flattened ventrally and ridged

Morphology Reproductive morphology Seeds

Seeds lanceolate to 5 mm long.

Note

The inflorescence of Abelia macrotera, like those of A. schumannii and A. uniflora, is composed of axillary flowers that are grouped towards the end of long branches, short shoots or in fascicules. Flowers of Abelia macrotera are bilabiate with a narrow tube and an expanded upper part. The tube can sometimes be more or less infundibuliform, as in A. macrotera var. parvifolia, or short and wide, as in A. macrotera var. deutziaefolia. The size of the corolla is variable, from 11 mm to 40 mm in length, and although there is no clear pattern, the corolla seems to be longer in taxa with smaller leaves, such as in A. macrotera var. mairei. The corolla mouth is bearded and has orange markings reaching the tube, except in var. deutziaefolia, where the markings are restricted to the mouth. The calyx has often been used to differentiate taxa in A. macrotera and we can see a distinction between sepals that have an acute apex, in varieties zabelioides, macrotera, henanensis, engleriana and mairei, and those with an obtuse apex, in varieties parvifolia, deutziaefolia and myrtilloides; nevertheless, this character is not consistent and many intermediates exist. Alhough the species could be very valuable in horticulture, Abelia macrotera is not known in cultivation.

Distribution

Abelia macrotera is widely distributed in China but is restricted to the western part of the country (Yunnan and Sichuan in the west, Gansu and Henan in the north, Hubei and Hunan in the east, and Yunnan and Guangxi in the south). The northern limit of A. macrotera is Henan and it reaches its southern limit in northern Vietnam (Meo Vac).

Ecology

The species is distributed in a wide array of habitats (including roadsides, woodlands, scrublands and hills) but is restricted to mountains and deep valleys around the Sichuan basin and east of the Qinghai Tibetan Plateau (QTP) between 600 and 2,200 m altitude.

Use

Young leaves are used to make grass jelly (Liangfen 凉粉) in Henan (Ding 1997) or incorporated into Tofu in Hubei (Fu 2001).