Psychotria hexandra var. oahuensis

O.Deg. & Fosberg (1964)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-Asterids Order: Gentianales Family: Rubiaceae Genus: Psychotria

Description

Key Characters:

Growth Form: Trees or shrubs up to 6 m tall.

Stems:

Roots:

Leaves: Leaves simple. Opposite. Blades obovate to oblanceolate, 3.1–20.8 cm long, 1.3–9 cm wide. Apex acute and often with a very pronounced, acute tip. Base acute or attenuate. Surfaces glabrous to pubescent; blades membranous, chartaceous, or coriaceous, domatia small and inconspicuous. Margins entire. Lateral veins 7–12 pairs. Petioles 0.4–3 cm long at base. Stipules irregularly obovate, up to 15 mm long.

Flowers: Flowers in inflorescences either with 1 main axis or 2–3–branched, or trichotomous from base, up to 12 cm long, with dichotomous branching, ultimate branches usually terminated by a 3–flowered cymule, central flower short–pedicellate or sessile, lateral flowers of the cymule usually sessile, subtended by opposite sterile bracts. Flowers insect-pollinated, unisexual, usually heterostylous, usually 6-merous. Calyx glabrous or pubescent, 4–5.5 mm long, usually shorter than hypanthium, expanded toward apex, truncate or lobed. Corolla white, apex acute in bud, the tube 6–13 mm long at anthesis, expanded toward apex, throat pubescent, the lobes 4-6, narrowly ovate–subulate or linear, as long as the tube or much longer, reflexed at anthesis; nectary disk present at apex of ovary. Stamens as many as and alternate with the corolla lobes, staminal filaments short, usually inserted on the corolla tube or throat; anthers attached ca. ⅓ from base, exserted at anthesis in functionally staminate flowers, narrow, somewhat curved, 4–6 mm long, dithecal, opening by longitudinal slits. Ovary inferior, occasionally partly so, or very rarely superior, ca. 4 mm long at anthesis, 2–celled, placentation basal; ovules 1 per cell, erect, anatropous; style as mamy as carpels, terminal, slender 4–6 mm long; stigmas 2, 2–lobed; stigmas of functionally pistillate flowers 3–6 mm long, terete (cylindrical) with the ventral surface often flattened and papillose or puberulent, dry or occasionally wet.

Fruit: Fruit drupaceous; orange; cylindrical to fusiform; broadly ellipsoid; or narrowly and asymmetrically ovoid; 8–18 mm long; 5–8 mm in diameter; usually crowned by the persistent calyx 2–4.5 mm long; pyrenes 1-2(-4) flat on ventral surface; dorsal surface angled; almost triangular in cross section; endocarp usually thick and hard. Seeds 1 per pyrene; usually conforming to the form of the pyrene; seed coat thin; without invagination; endosperm otherwise not ruminate; carnose; the embryo small with flat; thin cotyledons; seeds with well-developed oily endosperm; or endosperm occasionally scanty or absent.

Ploidy:

Habitat: Occurring in mesic to wet forest.

Elevation Range: 400–580 m.

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Endemic

Island Status

O'ahu Endemic

Dispersal Agents


Pollinators

Bibliography

Name Published In: Brittonia 16(3): 261 (1964)

Other References

Wagner et al. 1990:1166 (O)

Occurrences

SNo. Scientific Name Scientific Name Authorship Locality Habitat Basis of Record Recorded By Record Number Island Source Date