Brookea auriculata Yamazaki (1994: 282)

Neo, Louise, Huurne, Suzanne Ter & Adema, Frits, 2019, A taxonomic revision of the genus Brookea (Plantaginaceae), Phytotaxa 403 (3), pp. 171-186 : 173-174

2. Brookea auriculata Yamazaki (1994: 282) .

Type: — BORNEO. East Kalimantan: Bulungan, Long Bawan, Gunung Paris , 1000–1100 m, 13 Sep. 1990, Kato et al. 23805 (holotype TI [ TI00002287 ]; isotype TI [ TI00002286 ]) .

Shrub. Twigs terete, densely covered by short reddish, dendroid hairs. Leaves sessile, auriculate, ± semi-amplexicaul, elliptic, narrowly ovate or ± rhombic, 5–15 by 2.5–7 cm, index 2.0–2.8, base decurrent, semi-amplexicaul, margin finely denticulate, apex acuminate, above ± scabrous (see notes), below densely hirsute, with dendroid and stellate hairs, midrib and nerves ± sunken above, nerves 9–12 pairs, 3–9 mm apart. Inflorescences 3–12 cm long, peduncle 5–8 mm long, densely reddish villous. Bracts ovate, 3–5 mm long, (both sides) reddish villous. Pedicels 3–5 mm long. Calyx tubular, c. 10 mm long, teeth triangular; outside densely villous with dendroid and stellate hairs, inside densely long hairy, longest hairs 1.5–2.5 mm long; in fruit ovoid, not torn. Corolla c. 15 mm long, tube c. 10 mm long, upper lip bilobed, lobes orbicular, c. 3 by 3 mm, slightly denticulate, lower lip 3-lobed, lobes orbicular, c. 3 by 3 mm, slightly denticulate, middle lobe somewhat smaller, outside glabrous. Stamens: filaments hairy at base. Ovary ovoid, glabrous; style c. 5 mm long. Fruits ovoid, c. 10 by 5 mm, glabrous. Seeds subglobose, 0.4–0.6 by 0.4–0.5 mm, finely pitted.

Distribution: —Borneo: East Kalimantan ( Fig. 2 ).

Habitat: —Elevation: 1000–1100 m.

Notes: —This species is only known from the type collection. It is distinct from all other species of Brookea in its sessile, auriculate leaves. The leaf upper surface is ‘scabrous’ owing to the basal remnants of broken-off hairs. On the twigs, lower leaf surfaces and calyces, most or all hairs are short and dendroid, and on the lower leaf surfaces they are mixed with stellate hairs. B. auriculata can resemble B. dasyantha , which also has sessile leaves that may be slightly auriculate, but it is clearly different in the indumentum— B. auriculata has mainly short dendroid hairs not mixed with long unbranched hairs, while B. dasyantha has, especially at the twigs and inflorescence axes, many long, soft, unbranched hairs.

Figures

FIGURE 2. The distribution of B. tomentosa (white circle ○), B. dasyantha (black circle ●) and B. auriculata (black triangle ▲). Grey shaded areas are 1000 m and above in elevation.