Flora of the Hawaiian Islands
Literature for Myoporum sandwicense
Wagner et al., 1990, 1999; Chinnock, 2007. Literature for Myoporum sandwicense subsp. sandwicense
Chinnock, 2007. Literature for Myoporum sandwicense subsp. lanaiense
Chinnock, 2007.
   Scrophulariaceae -- The Butterfly Bush, Figwort Family Bibliography
      Myoporum sandwicense
General Information
DistributionEndemic to the Hawaiian Islands although the two subspecies have well-defined boundaries.
Shrub or small tree 1—10(-20) m tall. Branches slightly flattened towards tips, with shallow furrows often extending down from leaf bases, smooth but often longitudinally ribbed when dry, non-tuberculate or rarely with a few obscure tubercles, glabrous or occasionally eglandular or glandular-pubescent, glandular-papillate, resinous towards tips.
Leaves alternate, flat to canaliculate, linear to widely elliptic or lanceolate or rarely obovate, acute to long attenuate or, rarely, broadly acute or obtuse, gradually tapering to a winged petiole-like base 5.0—20(-35) mm long; margins entire or obscurely serrate, or more rarely prominently serrate (especially seedlings and regrowth); surfaces concolorous or discolorous, adaxial surface often deeper green, midrib sunken, midrib prominently raised on abaxial side, (42-)60-135(-220) x (5-) 11-25(-45) mm; glabrous or sparsely to densely glandular or eglandular-pubescent on both surfaces or restricted to abaxial one.
Flowers 2—6(-12) per axil; pedicel terete or flattened in lower part, terete above and more or less 5 or more ribbed when dry, 4.5—18 mm long, glabrous or rarely glandular- or eglandular-pubescent. Sepals 5—6(-9), often variable in same cyme, imbricate at base, lanceolate or triangular, acute to attenuate, margins usually slightly membranous and translucent in basal part, veins not pronounced on inner surface when dry, 2-6 x 0.9—2.3 mm, outer surface glabrous or rarely glandular- or eglandular-pubescent, margins sparsely glandular-pubescent but sometimes with longer eglandular hairs; inner surface glandular-puberulous. Corolla white, white tinged pink or pink, blotched darker pink at base of lobes, unspotted or very rarely purple spotted at base of lobes, translucent gland spots often obvious, prominent pellucid gland spots more obvious in dried material; lobes (4-)5(-8) x 2-3.5(-7.5) mm long, equal to or longer than tube, obtuse; tube 1.5-3.5 (-5.5) mm long; outside surface glabrous, inside surface of lobes and tube glabrous or sparsely to densely pubescent. Stamens 5(rarely 4 or 6 in some flowers), shortly exserted; filaments glabrous or pubescent in basal part; anthers glabrous. Ovary ovoid-conical, 5-10(-12)-locular with 1 ovule per locule, 1.5-3.5 x 1-1.6 mm, glabrous; style glabrous or pilose.
Fruit drupaceous, subglobular, ovoid, more rarely depressed conical or lenticular, 3—10 x 3—11 mm; exocarp greenish white, cream or pale yellow, rarely tinged pinkish or purplish pink; mesocarp succulent, watery; endocarp woody, variable in shape, subglobular, ovoid to depressed ovoid or more or less lenticular, almost smooth to prominently ribbed, rounded or distinctly beaked at apex.
Seed oblong, 2.4—2.5 x 0.8—0.9 mm, white.
Chromosome number unknown.
Myoporum sandwicense is extremely polymorphic, ranging from a low decumbent shrub to a small tree to 20 m with a trunk circumference of up to 0.9 m. Leaves are extremely variable in their shape, size, margin and pubescence. The flower parts range in number from 5—9 and fruits are variable in shape and can be smooth to prominently ribbed and have 5—12 locules.
Nancy Khan