Hydrangea liukiuensis
Sponsor
Kindly sponsored by a generous supporter who loves hydrangeas.
Credits
Julian Sutton (2025)
Recommended citation
Sutton, J. (2025), 'Hydrangea liukiuensis' from the website Trees and Shrubs Online (treesandshrubsonline.
Synonyms
- Hydrangea scandens subsp. liukiuensis (Nakai) E.M.McClint. (in part)
- Hortensia liukiuensis (Nakai) H.Ohba & S.Akiyama
Other taxa in genus
- Hydrangea ampla
- Hydrangea angustipetala
- Hydrangea anomala
- Hydrangea arborescens
- Hydrangea arborescens Species Complex Cultivars A–M
- Hydrangea arborescens Species Complex Cultivars N–Z
- Hydrangea aspera
- Hydrangea aspera Species Complex Cultivars
- Hydrangea barbara
- Hydrangea bretschneideri
- Hydrangea cinerea
- Hydrangea daimingshanensis
- Hydrangea davidii
- Hydrangea fauriei
- Hydrangea febrifuga
- Hydrangea glaucescens
- Hydrangea heteromalla
- Hydrangea heteromalla Species Complex Cultivars
- Hydrangea hirsuta
- Hydrangea hirta
- Hydrangea hwangii
- Hydrangea hydrangeoides
- Hydrangea indochinensis
- Hydrangea integrifolia
- Hydrangea Intersectional Hybrids
- Hydrangea involucrata
- Hydrangea kawakamii
- Hydrangea kwangsiensis
- Hydrangea lobbii
- Hydrangea longifolia
- Hydrangea longipes
- Hydrangea luteovenosa
- Hydrangea macrophylla
- Hydrangea obtusifolia
- Hydrangea paniculata
- Hydrangea paniculata Cultivars A–D
- Hydrangea paniculata Cultivars E–I
- Hydrangea paniculata Cultivars J–L
- Hydrangea paniculata Cultivars M–R
- Hydrangea paniculata Cultivars S–Z
- Hydrangea petiolaris
- Hydrangea platyarguta
- Hydrangea pottingeri
- Hydrangea quercifolia
- Hydrangea radiata
- Hydrangea robusta
- Hydrangea sargentiana
- Hydrangea scandens
- Hydrangea schizomollis
- Hydrangea Section Macrophyllae Cultivars A
- Hydrangea Section Macrophyllae Cultivars B
- Hydrangea Section Macrophyllae Cultivars C
- Hydrangea Section Macrophyllae Cultivars D
- Hydrangea Section Macrophyllae Cultivars E–F
- Hydrangea Section Macrophyllae Cultivars G
- Hydrangea Section Macrophyllae Cultivars H
- Hydrangea Section Macrophyllae Cultivars I–J
- Hydrangea Section Macrophyllae Cultivars K
- Hydrangea Section Macrophyllae Cultivars L
- Hydrangea Section Macrophyllae Cultivars M
- Hydrangea Section Macrophyllae Cultivars N–O
- Hydrangea Section Macrophyllae Cultivars P–Q
- Hydrangea Section Macrophyllae Cultivars R
- Hydrangea Section Macrophyllae Cultivars S
- Hydrangea Section Macrophyllae Cultivars T–U
- Hydrangea Section Macrophyllae Cultivars V–Z
- Hydrangea seemannii
- Hydrangea serrata
- Hydrangea serratifolia
- Hydrangea sikokiana
- Hydrangea species of Section Cornidia
- Hydrangea species of Sections Cardiandra and Deinanthe
- Hydrangea strigosa
- Hydrangea stylosa
- Hydrangea tomentella
- Hydrangea × versicolor
- Hydrangea viburnoides
- Hydrangea villosa
- Hydrangea xanthoneura
- Hydrangea × ytiensis
Deciduous or semi-evergreen shrub to 1.5 m, with sparse, ascending branches. Bark peeling in longitudinal strips. Current year’s branchlets red-brown, with sparse, short, appressed hairs; winter buds narrowly obovoid, 3–5 mm long. Leaves opposite. Leaf blade elliptic, 3–4 cm long; both surfaces with short hairs along the veins and densely in the vein axils; base cuneate to rounded; margin has a few low serrations towards the apex; apex obtuse; petiole 0.5–0.8 cm. Inflorescence a few-flowered, sessile corymb 2–4 cm across; branches with curled hairs; only fertile flowers present. Fertile flowers ~8 mm across, on pubescent pedicels 2–3 mm long; calyx tube cup-shaped, with 5 spreading, triangular or broadly ovate lobes; petals 5, free and reflexed, white, obovate-oblong to oblanceolate, ~1.5 mm long, sometimes falling early; stamens 10, erect and unequal, 3–4 mm long with petal-coloured filaments; ovary half inferior; styles 3(–4), erect and slightly swollen at anthesis. Fruit an ellipsoid or ovoid capsule 3–5 mm long, dehiscing apically between the styles. Seeds ellipsoid, ~0.8 mm, with a short wing at one end. Flowering February–April (Japan). (Ohba 2001).
Distribution Japan Okinawa
Habitat Evergreen forests.
USDA Hardiness Zone 9-10
RHS Hardiness Rating H3
Conservation status Not evaluated (NE)
This demure but distinctive member of the H. scandens/pottingeri complex is probably not in cultivation, but included here for clarity because the name is sometimes seen in collections. It was originally described from Okinawa (Nakai 1911), differing from H. scandens in its complete lack of sterile flowers, as well as longer anthers and papillate stigmas. Its leaves are also thicker and smaller than those of H. scandens (3–4 cm versus 4–7 cm long – Ohba 2001), elliptic and strikingly toothed. Japanese floras have consistently reserved the name for this Okinawan endemic (Ohwi 1965; Ohba 2001). It is unlikely to prove very hardy in our area, given Okinawa’s humid, subtropical climate.
McClintock (1957) lumped H. liukiuensis (whose type specimen she had not seen) with the similarly small-leaved H. luteovenosa in H. scandens subsp. liukiuensis. This is the probably why garden plants with significant numbers of sterile flowers and only modestly toothed leaves, looking much more like H. luteovenosa, are sometimes labelled H. scandens subsp. liukiuensis or H. liukiuensis.
Crûg Farm collections labelled H. scandens subsp. liukiuensis, made from streamsides around 600 m asl on Yakushima in 2006 (BSWJ 11471 & 11499) are described as small twiggy shrubs to 1 m tall, with slender, very dark red-brown branchlets, and small, deeply serrated leaves 3–4 cm long. Inflorescences are white ageing yellow, in most of the upper leaf axils (Crûg Farm Plants 2024). The distribution and description together might suggest H. kawagoeana var. grosseserrata (not covered here).
