Geniostoma

Geniostoma ligustrifolium, from here.

Belongs within: Loganiaceae.

Geniostoma is a genus of about fifty species of small trees and shrubs found in south-east Asia and Australasia. Species have been divided between two sections, with the species G. umbellatum (known only from Guadalcanal in the Solomon Islands) set apart from others by its unusually large stipules (Conn 1995).

Characters (from Conn 1995): Small shrubs to small trees, rarely scrambling to semi-climbing. Branches terete, quadrangular or four-winged, variously hairy or glabrous. Stipules mostly intrapetiolar. Leaves simple, opposite, more or less petiolate or sessile. Inflorescences terminal or axillary, ramiflorous or cauliflorous, uniflorous, dichasial or pleiochasial, often umbelliform or glomerulate. Calyx, corolla and androecium pentamerous. Sepals united at base; inner surface of calyx often with colleters at base; lobes imbricate in bud, margin mostly fimbriate. Corolla campanulate to rotate, white; outer surface glabrous to shortly hairy; inner surface glabrous to densely pilose; lobes imbricate or contorted in bud. Stamens alternipetalous, attached to mouth of corolla tube, exserted, usually recurved after anthesis, glabrous or hairy; filaments mostly short; anthers bilocular, introrse, connective often extended to form apical appendage. Pistil variously hairy or glabrous; ovary bilocular; placentas axile with many amphitropous ovules; style mostly short; stigma clavate, ellipsoid to globular, sometimes more or less oblong, about as large as ovary. Capsule ellipsoid to globular, sometimes more or less oblong, rarely flattened-ellipsoid, bivalved, septicidal to subseptifragal, maturing to green, with or without a black-purple tinge, usually becoming brown-black when over-mature. Seeds embedded in juicy orange or red pulp, numerous, ellipsoid to subglobular, intruded on hilar side; surface mostly minutely papillose to areolate, brown to black, endosperm thick, fleshy; embryo small, straight.

Geniostoma Forster & Forster 1776 A61
    |  i. s.: G. ligustrifolium Cunn. 1839 A61 (see below for synonymy)
    |--G. sect. Geniostoma C95
    |    |--G. antherotrichum Gilg & Bened. 1916 C95
    |    |    |--G. a. var. antherotrichum [incl. G. arfakense Kan. & Hat. 1942] C95
    |    |    `--G. a. var. archboldianum (Merr. & Perry) Conn 1980 [=G. archboldianum Merr. & Perry 1942] C95
    |    |--G. leenhoutsii Conn 1980 C95
    |    |--G. randianum Merr. & Perry 1942 [incl. G. obtusum Merr. & Perry 1942] C95
    |    |--G. rupestre J. R. & Forster 1776 [incl. G. stenophyllum Gilg. & Bened. 1916] C95
    |    |    |--G. r. var. rupestre (see below for synonymy) C95
    |    |    |--G. r. var. crassum L97 [=G. ligustrifolium var. crassum Cheeseman 1897 A61]
    |    |    |--G. r. var. glaberrimum (Benth.) Conn 1980 [=G. crassifolium var. glaberrimum Benth 1857] C95
    |    |    |--G. r. var. moluccanum (Bl.) Conn 1980 (see below for synonymy) C95
    |    |    |--G. r. var. rouffaeranum Conn 1980 C95
    |    |    `--G. r. var. solomonense Conn 1980 C95
    |    |--G. trichostylum Conn 1980 C95
    |    `--G. weinlandii Sch. in Sch. & Laut. 1905 [incl. G. acutifolium Hiern 1909] C95
    `--G. (sect. Macrostipulare) umbellatum Conn 1980 C95

Geniostoma ligustrifolium Cunn. 1839 A61 [=G. rupestre var. ligustrifolium MM04; incl. G. ligustrifolium var. major Cheeseman 1906 A61]

Geniostoma rupestre var. moluccanum (Bl.) Conn 1980 [=G. lasiostemon var. moluccanum Bl. 1850; incl. G. dallmannense Kan. & Hat. 1942] C95

Geniostoma rupestre J. R. & Forster 1776 var. rupestre [incl. G. acuminatissimum Gilg. & Bened. 1916, G. brassii Merr. & Perry 1942, G. caulocarpum Sch. 1905, G. dasyneuron Gilg. & Bened. 1916, G. psychotrioides Gilg. & Bened. 1916, G. pullei Cammerl. 1924, G. schlechteri Gilg. & Bened. 1916] C95

*Type species of generic name indicated

REFERENCES

[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).

[C95] Conn, B. J. 1995. Loganiaceae. In: Conn, B. J. (ed.) Handbooks of the Flora of Papua New Guinea vol. 3 pp. 132–188. Melbourne University Press: Carlton (Australia).

[L97] Lange, P. J. de. 1997. Hebe brevifolia (Scrophulariaceae)—an ultramafic endemic of the Surville Cliffs, North Cape, New Zealand. New Zealand Journal of Botany 35: 1–8.

[MM04] Martin, N. A., & L. A. Mound. 2004. Host plants for some New Zealand thrips (Thysanoptera: Terebrantia). New Zealand Entomologist 27: 119–123.

Last updated: 27 October 2019.