Ephedra milleri

Freitag & Maier-St. 1992

Common names

Taxonomic notes

A molecular analysis has found Ephedra milleri to be fairly basal within Ephedra; one algorithm found it to be the sole occupant of a clade sister to all other Ephedra except a few basal taxa that are all native to the Mediterranean region; a second algorithm incorporated it within that basal clade (Rydin and Korall 2009). Either way, it appears to be a good species, despite a very limited number of collections to date.

Description

Dioecious shrubs to 0.8 m tall, erect. Branches erect or arched upright, stiff, (1.2-)1.5-2.5(-3.2) mm thick, whorled or opposite. Bark green or grey-green, grooved, (pappilose-) tuberculate; pith parenchyma dark. Leaves 2 or 3, 1.5-2(-2.5) mm long, connate for 1/2 to 4/5 their length, with a membranous, papillose-ciliate margin. Pollen cones solitary or few (2–3), pedunculate; peduncles often 2, opposite, very unevenly, (1—)5—7(—9) mm long, the bracts ovate to obovate, ± cucullate, 2.5–3 x 1.2–1.5 mm, with an obtuse apex and membranous margin, finely papillose-ciliate. Sporangiophores ±5, sessile, protruding 0.5-1 (-1.5) mm from the bracts. Seed cones solitary, short-pedunculate, axillary, or few (2–3), with solitary or opposite peduncles up to 8 mm long; bracts c. 1/2 connate, obtuse or apiculate, with a membranous margin, papillose-ciliate; mature cones fleshy, reddish; two seeds, usually 1 is aborted; dark-brown, 6-7.5 x 2.5mm, narrowly ovate, truncate, the ventral surface nearly flat, the dorsal surface convex, broadly rounded and keeled (Freitag and Maier-Stolte 1992).

Regarding similar species, it "looks much like E. pachyclada, which reaches Oman in the Musandam peninsula and in Jabal al-Akhdar. However, by the papillose to ciliate margins of leaf sheaths and of bracts, as well as by the pollen grain structure with simple, undivided furrows, it is more closely related to E. fragilis and E. aphylla. In these two species, however, the female cones are strictly 1-seeded, narrow cylindric in shape, and their bracts are fused for a longer distance. Furthermore, they have at least somewhat spreading main branches, and in addition E. aphylla differs by white color of the pith parenchyma and smaller number of anthers. In the occurrence of sometimes 3-merous leaves, bracts and flowers, the new species approaches E. foliata which occurs in the same area, but differs by a climbing habit, papillose or smooth stem surface, and only 3-4 anthers in the male flowers" (Freitag and Maier-Stolte 1992).

Distribution and Ecology

Oman: Dhofar, and S. Yemen (Bell and Bachman 2011). Climate semi-arid, with a slight monsoon. Associated species include a mixture of tropical deciduous (Acacia etbaica, Boswellia spp., Commiphora spp.), evergreen (e.g. Dracaena serrulata), aphyllous (Dhofaria macleishii) and succulent (e.g. Euphorbia balsamifera) species. Very similar ecological conditions and plant communities occur also further west up to N Yemen, so E. milleri may occur in that range as well (Freitag and Maier-Stolte 1992).

A 2021 review of herbarium collections revealed only 8 collections of the species, of which 7 appear to be the initial 1985 collections in Oman by Miller, with a single 2001 collection in Yemen. The "least concern" conservation assessment therefore appears to not be data-based; the species should likely be assessed as "data deficient".

Remarkable Specimens

No data as of 2023.03.03.

Ethnobotany

Observations

See the observations on iNaturalist, accessed 2021.12.30.

Remarks

The epithet honors A. G. Miller, who in 1985 collected the type specimen in Dhofar, Oman (Freitag and Maier-Stolte 1992).

Citations

Bell, A. and S. Bachman. 2011. Ephedra milleri. The IUCN Red List of Threatened Species 2011. https://www.iucnredlist.org/species/201669/9160690, accessed 2021.12.27.

Freitag, H. and M. Maier-Stolte. 1992. A new species and a new combination in the genus Ephedra from Arabia. Edinburgh J. Bot. 49:89.

Rydin, C., and P. Korall. 2009. Evolutionary relationships in Ephedra (Gnetales), with implications for seed plant phylogeny. International Journal of Plant Sciences 170(8):1031–1043. doi:10.1086/605116.

See also

Species profile at Plants of the World Online, accessed 2021.12.30.