Lagerstroemia subcostata Koehne

It is difficult to separate the following two species, Lagerstroemia glabra (including L. stenopetala) and L. caudata, from the widespread L. subcostata. Further knowledge about the degree of development of indumentum and variability of leaf shape and size is needed. More abundant gatherings may erase apparent differences between the species.

Trees or shrubs, to 14 m tall. Branchlets glabrous to gray puberulous or pubescent. Petiole 2-4 mm; leaf blade oblong, ovate-lanceolate, elliptic, obovate-elliptic, or infrequently obovate, 2-9(-11) × 1-5 cm, papery, abaxially glabrous or slightly pubescent, lateral veins 3-10 pairs, base broadly cuneate to subrounded, apex acuminate. Panicles pyramidal, 7-16(-30) cm, gray-brown pubescent, densely flowered. Floral tube 6-merous, 3.5-4.5 mm, with (10 or)12(or 14) dark veins or obscurely (10 or)12(or 14)-ribbed, glabrous to densely gray pubescent; sepals 1-2 mm, adaxially glabrous; annulus thin or apparently absent; epicalyx absent. Petals white, pink, or purple, broadly ovate with obtuse base, 7-10 mm including claw 3.5-6 mm, claw ca. as long as blade. Stamens 15-30, dimorphic. Ovary glabrous. Capsules globose to mostly oblong, 6-9(-11) mm, 3-6-valved. Seeds including wing ca. 4 mm. Fl. Jun-Aug, fr. Jul-Oct.

Forest margins, streamsides; low to medium elevations. Anhui, Fuian, Guangdong, Guangxi, Hunan, Hubei, Jiangsu, Jiangxi, Qinghai, Sichuan, Taiwan, Zhejiang [Japan, Philippines].

Lagerstroemia subcostata var. hirtella Koehne; L. unguiculosa Koehne.

Lagerstroemia subcostata (also known as the Taiwan crepe myrtle) is a deciduous tree which is native to Japan, Taiwan, China and the Philippines.

The flower has five or six creped petals. Five or six of the stamens are particularly long.

Flowers just opened.

Panicle and phyllotaxis (Opposite or alternate leaves).

Color of young leaves.

When the fruit is ripe it splits on its own.

Old bark is falling off. Smooth bark is a major feature of Lagerstroemia subcostata.

Tree trunks with diameter at breast height tend to be hollow.

Uses: soil and water conservation, firewood, farm tools and traditional Chinese medicine.