Monophyllaea grandifolia Kiew & S.Julia, 2013

Kiew, Ruth & Sang, Julia, 2013, Two new Monophyllaea (Gesneriaceae) species from Sarawak, Borneo, Phytotaxa 129 (1), pp. 59-64 : 59-61

Monophyllaea grandifolia Kiew & S.Julia , sp. nov. ( Figure 1 )

It differs from Monophyllaea hottae in its shorter peduncle (ca. 14 cm not ca. 30 cm long), its strongly recurved flowering axis and its smaller flowers (ca. 9 mm not ca. 13 mm long) with strongly reflexed upper lobes.

Type:— MALAYSIA. Borneo, Sarawak, Tatau District: Ulu Merirai , Gua Tiang , 6 July 2005, Julia et al. S 94648 (holotype SAR!; isotypes KEP!, SAR!, SING!) .

Stems (hypocotyls) (40–)50–70(–98) cm long, stout, in life dark green and succulent, 2–4 cm diameter. Leaves broadly ovate, 40–67 × 37–72 cm, green and glossy above, when fresh thickly succulent, base deeply cordate, lobes to 6 cm long, upper surface with occasional uniseriate hairs ca. 0.5 mm long, beneath becoming glaucous and completely encrusted with crystalline chalk pustules; lateral veins 16–25 pairs, radiating from the base, then parallel and (1–) 2–3.3 cm apart, midrib sunken above, prominent beneath, tertiary veins reticulate, slightly prominent. Inflorescences arising from base of midrib, up to 15–26 in various stages of development, peduncle (6–) 7–14 cm long, glabrous, flowering axis strongly recurved, slightly thickened, 1– 2.5 cm long, rarely with two branches, flowers arranged in 2 diverging rows; pedicels ca. 8 mm long. Calyx divided nearly to the base, glabrous, lobes broadly oval, ca. 2.5 × 2 mm, apex rounded and entire. Corolla ca. 9 mm long, yellowish with yellow palate or greenish with a whitish yellow palate, lobes 5, tube ca. 3 × 4 mm, densely bearded with long hairs inside below filaments, palate with dense glandular hairs, upper lobes ca. 2.5 × 3.5 mm, strongly reflexed, lateral and median lobes connate for 2 mm, lateral lobes orbicular, ca. 2.25 × 2 mm, median lobes spathulate, ca. 4 × 4 mm. Stamens glabrous, filaments ca. 2 mm long, posterior converging, anterior strongly curved with a rhomboid tooth ca. 1 mm long, anthers globose, ca. 1 mm diameter. Ovary globose, ca. 1 mm diameter, greenish, style ca. 2 mm long, stigma greenish or purple. Fruits with pedicel to 12 mm, ascending at ca. 45 o, capsule globose, ca. 2 mm diameter, style persistent and exserted from the calyx.

Distribution:— Endemic to Sarawak, Borneo; known only from the limestone areas in Ulu Merirai, Tatau district.

Habitat:— Quite widespread in the Ulu Merirai limestone area where it grows at the base of (but not on) the limestone rock face and is particularly common and can form drifts on damp slopes on limestone-derived soil or in swampy areas at the base of limestone cliffs, at 131–280 m elevation. It apparently flowers continuously because a single plant produces a series of inflorescences in all stages of development.

Other specimens examined:— MALAYSIA, Borneo, Sarawak: Tatau District, Ulu Merirai , Gua Aki Bukok , 10 July 2005, Julia et al. S 91196 ( SAR); Path to Gua Bukit Linggong (2 o 48′ 34′′ N, 113 o 40′ 25′′ E), 14 July 2005, Leong et al. PL 331 ( SAR, SING) .

Notes:— It is most similar to Monophyllaea hottae which grows on the Melinau limestone in the Gunung Mulu National Park, in its large leaves which are densely encrusted beneath, inflorescences arising from the base of the midrib and its calyx divided almost to the base. It differs in the characters listed in Table 1. This new species is named for its large leaf. Two other Monophyllaea species produce large leaves: M. hottae has leaves up to 60 × 40 cm and M. sarangica Burtt (1978: 43) has leaves up to 69 × 52 cm ( Kiew et al. 2007) but none are as large as those of M. grandifolia that can grow to 67 × 72 cm (in spite of the apex rotting away) making them the widest in the genus. The plant is extremely succulent and has a stout fleshy stem that can grow to 98 cm long and ca. 4 cm thick.

Figures

FIGURE 1. Monophyllaea grandifolia Kiew & S.Julia. A. habit; B. flowers and fruits (all photos from Julia et al. S 94648 by P.K.F. Leong).