Alyxia

Alyxia latilitnba Grant

Frutex, 1.5–2 m altus, glaber, ramulis triangulatis vel subalatis, 2–3 mm crassis; folia verti-cillata terna sessilia vel petiolata, petiolis ad 4 mm longis, laminis late obovatis ellipticis vel vix ovatis 3.5–5.6 cm longis 2–3 cm latis basi cuneatis vel subrotundatis apice obtusis interdum parum attenuates coriaceis nitentibus lutei-viridibus subtus pallidi-oribus margine revolutis; cymae axillares 4-floriferae, pedunculis 10–15 mm longis, pedicellis 5 mm longis; calyx viridis tubo 0.4 mm longo, lobis ovati-lanceolatis 1.2–1.5 mm longis obtusis apice ciliolatis; corolla infundibulariforma lutea, tubo 5.5–6.5 mm longo 1–1.5 mm infra faucem parum dilatato parte supera intus villosa, lobis ovatis vel suborbiculatis parum asymmetricis 2.8–3 mm longis 2.5–3 mm latis, apice rotundatis ciliolatis; stamina filamentis 0.3–0.5 mm longis, antheris ovati-lanceolatis 1 mm longis includentibus; ovaria bina 0.6 mm longa basi longe villosa; stylus sin-gulus 4–4.5 mm longus glaber; stigma ovatum 0.6 mm longum barbatum; drupae geminatae ellipticae vel subglobosae (vel saepe dispermae moniliformae) 13 mm longae 12 mm latae 9 mm crassae parum apiculatae.

Shrub, 1.5–2 m high, glabrous. Twigs prominently 3-angled or subwinged, 2–3 mm thick, brown or gray, lenticels not prominent. Leaves verticil-late, in 3's, sessile or on petioles to 4 mm long, broad, obovate, elliptical or scarcely ovate, 3.5–5.6 × 2–3 cm, cuneate or rounded at base, obtuse and occasionally somewhat attenuate at the tip, coriaceous, shining, yellowish green, somewhat paler below, revolute, with 14–18 inconspicuous lateral veins. Cymes 4-flowered, peduncles 10–15 mm long, pedicels 5 mm long. Calyx tube 0.4 mm long; lobes ovate-lanceolate, 1.2–1.5 mm long, obtuse, ciliolate at the tip. Corolla salverform, yellow; tube 5.5–6.5 mm long, slightly expanded 1–1.5 mm below the throat; lobes ovate to suborbicular, somewhat asymmetrical, 2.8–3 × 2.5–3 mm, rounded at the tip, which is faintly ciliolate. Filaments 0.3–0.5 mm long; anthers ovate-lanceolate, 1 mm long, acute. Ovaries 2, 0.6 mm long, long-villous at the base; style 4–4.5 mm long; stigma ovoid, 0.6 mm long, bearded at the tip. Drupes (submature?) geminate, elliptical or subglobose (when 1-seeded), flattened ventrally, 13 × 12 × 9 mm, frequently moniliform (2-seeded) and then longer, minutely or not at all beaked, greenish. Embryo 7 mm long; cotyledons curved.

In leaf shape the species is rather close to A. scandens, but the leaves are much broader in proportion, more coriaceous, and somewhat more conspicuously revolute. The flowers are about ⅔ as large and the corolla lobes about half as long as in A. scandens. The species is named with reference to the broad blades and broad corolla lobes.

The St. John specimens cited below probably belong here, though we have no record of the shape of the corolla lobes. If these specimens do belong here the plant may reach 3 m tall and the ripe fruit is black, becoming 17 mm long.

RANGE.—Society Islands: Borabora: Grant 4964, Tevaitapu, Mt. Tarapaia, alt. 560 m (1840 ft), ridge scrub, 3 January 1931, flower and fruit (BISH, type; MIN). Tahaa: Grant 5162, Ruutia, Mt. Ohiri, alt. 465 m (1525 ft), Morinda-Crossostylis forest, 25 January 1931, flower and fruit (BISH, MIN); St. John 17397 and 17402, Mt. Purauti, alt. 420–500 m, ridge thicket, 11 October 1934, flower and fruit (17397), fruit (17402) (BISH).

LOCAL NAME.—Borabora and Tahaa: pitoa.

Alyxia stelfaa var. deckeri Fosberg & Sachet

Alyxia stellata var. deckeri Fosberg & Sachet, Micronesica, 10:254, 1974.

Leaves broadly ovate, subcordate to cordate, cymes 4 cm long, flowers about 6 mm long, fruit segments subglobose, 10 × 12 mm, black.

Known only from high elevations of Hiva’oa, in cloud forest.

SPECIMENS SEEN.—Hivaoa I.: Atuona-Feani Trail, crest of ridge, 1200–1300 m, Sachet & Decker 1151 (US, type, P, Fo, BISH, NY, K).

Alyxia is an Australasian genus of flowering plant in the dogbane family, Apocynaceae. It contains at present 106 species, but Alyxia stellata and A. tisserantii are very variable, might be cryptic species complexes, and are need of further study. It consists of shrubby, climbing or scrambling plants. This genus occurs in China, the Himalayas, Southeast Asia, Australia, New Caledonia and the Pacific Islands. There are 14 species in Australia, 21 in New Caledonia and 7 in the other Pacific Islands, including Hawaiʻi.

The leaves are opposite or in whorls of three to seven. There are colleters (groups or tufts of mucilaginous secretory hairs) present in the leaf axils. The inflorescence is axillary or terminal with solitary flowers or simple cymes. Flowers consist of five petals and five sepals. The flowers have a slender tube which expands abruptly. The stamens have short filaments and are inserted in the upper half of the corolla. The fruit is a pair of drupes, originating from each flower.

Dysentery bush (A. buxifolia) is used in herbalism and was made into a patented remedy by Albert Aspinall. Maile (A. oliviformis), endemic to the Hawaiian Islands, has sweet-smelling leaves and is much used for lei; formerly it was reserved for aliʻi (nobility), but today it can be used by anyone and is a popular wedding decoration on the islands. Maile also provides food for Thyrocopa caterpillars and belid weevils of the genus Proterhinus. Alyxia spp. are also used in Jamu.