Steven Hammer

Observations on pollination and hybridization in the genus Conophytum (Mesembryanthemaceae)

Summary. Field observations on pollination are reported in 14 species of the genus Conophytum. The pollination pattern observed is discussed in relation to floral specializations found in the genus. Observations in sympatric populations reveal considerable hybridization between some species.

Conophytum: an annotated checklist (A-C)

Zusammenfassung. Conophytum: Eine kommentierte Liste (A-C). Fur die Gattung Conophytum wird eine kommentierte Liste der veroffentlichten Namen begonnen, die in voraussichtlich drei Fortsetzungen beendet sein wird. Fur alle aufgenommenen Namen werden Autor, Publikationsort, Details der Typifizierung und wichtigste Synonyme angegeben. Akzeptierte Artnamen werden von Angaben zur infragenerischen Zugehorigkeit, einer kurzen Beschreibung, Verbreitungsinformationen und kritischen Bemerkungen begleitet.

Macro-Observations on Cheiridopsis N.E.Br. and Odontophorus N.E.Br. (Aizoaceae)

Summary: Cheiridopsis N.E.Br., a southern African genus in the Aizoaceae Rudolfi, was recently revised by Hartmann and Dehn (1987). A number of lost species have subsequently been rediscovered; several new species, and forms linking some of the accepted species, have also been discovered. These are discussed and illustrated. Two species, C. delphinoides S.A.Hammer and C. velox S.A.Hammer, are newly described. Odontophorus N.E.Br., closely allied to Cheiridopsis, is also briefly examined. A new taxon, O. angustifolius L. Bolus subsp. protoparcoides S.A.Hammer, is described and illustrated.

Odes Part Two: Descriptions of New Mesembryanthema

Summary: Four new taxa in Aizoaceae are described: 1 species and 2 subspecies in Conophytum, and 1 species in Delosperma.

Conophytum bachelorum and its relatives: the introduction of a new conophytum from Namaqualand, C. confusum.

Summary: A reassessment of a group of four closely related taxa of the dwarf succulent genus Conophytum from Namaqualand, South Africa has been undertaken. This has resulted in the description of a newly discovered taxon, namely Conophytum confusum.

Conophytum crateriforme - a new dumpling from Namaqualand

Summary: A new taxon in the dwarf succulent genus Conophytum from Namaqualand, South Africa is described - Conophytum crateriforme. The plant is named for its distinctive bowl shape.

Flower Pigment Patterns and Systematics of Conophytum N. E. Br. (Aizoaceae)

Abstract In an older paper, Reznik (1957) studied flower pigments from 37 Conophytum samples and found three main pigments: one betaxanthin (in samples with yellow flowers) and two betacyanins (betanin 1 in samples with purple flowers and betanin 2 in one sample with rose-purple flowers), as well as 6 flavonols as co-pigments. Here, the results from Reznik (1957) and related older studies are compared with more recent morphological-phylogenetic studies (Opel 2005b) with regard to the agreement or deviation with respect to subdivisions of the genus Conophytum. The mutually exclusive distribution of two flavonols in Conophytum is phylogenetically informative: flavonol 1 is restricted to the basally diverging lineages of the Biloba Grade (including Conophytum taylorianum), and flavonol 2 was found in the group containing the remainder of Conophytum, probably indicating monophyly. In conjunction with phylogenetic data of Opel (2005b), floral pigment data suggest that Conophytum sect. Biloba could be provisionally recognized as a possibly paraphyletic assemblage comprising all members of the Biloba Grade including C. taylorianum but excluding C. herreanthus, and that sect. Herreanthus should encompass C. herreanthus only.

Tylecodon opelii, a new obligatory quartz-gravel species from the Northern Knersvlakte (Western Cape, South Africa)

Some 47 species of Tylecodon are endemic to South Africa and Namibia (Van Jaarsveld & Koutnik 2004). In South Africa 43 species occur, confined to the south – and south-western portion of the country where winter rainfall is experienced. The new species falls within the Knersvlakte Centre of Plant Endemism (Van Wyk & Smith 2001). Tylecodon opelii is a new, obligate quartz-gravel dwelling species endemic to the northern Knersvlakte in the northern part of the Western Cape Province of South Africa. It was discovered by, and is named for, Conophytum expert Matt Opel, of the University of Connecticut (USA), on a expedition to the Knersvlakte July 2000. It is related to a group of dwarf, quartz-dwelling, geophytic species growing mainly in Succulent Karoo vegetation: Tylecodon nolteei, T. occultans, T. pusillus and T. peculiaris. Tylecodon opelii is immediately distinguished from other species by its oblong tubers, and its irregularly moulded leaves, which are intensely dark green during the growing season, bearing a few pointed trichomes. The corolla of T. opelii is cylindric to slightly funnel-shaped, 12-14 mm long, with tapering squamae at the base. The species can be confused with T. occultans and T. nolteei. However, T. occultans is immediately recognised by the white whiskery trichomes on its much broader leaf surfaces, T. nolteei (Fig. 1) by its blood-red, Gorbachev-forehead markings. T. occultans and T. opelii never have these painted markings, and T. nolteei has a larger, much taller caudex, though that pertains more to plants at the type locality; the eastern and southern populations show rounder, more modest caudexes. Tylecodon peculiaris (Fig. 2) is another very little-known plant with which T. opelii can also be confused, but it is immediately distinguished by its rough ‘jellytot’ appearance, the epidermis having a glassily bubbled purplish-green texture. Tylecodon opelii Van Jaarsv. & S.A.Hammer, differt a T. occultante tuberibus oblongis, foliis atroviridibus, irregulariter contortis, trichomata acuta sparse ferentibus, corolla 12–14 × 2–3 mm ad orem tubo alba differt. TYPE.—SOUTH AFRICA 3118 (Vanrhynsdorp): Bakoondkolk, south-sloping quartz gravel hillside, 150–200 m, (–AB), Van Jaarsveld 22751 (NBG, holo.). Plant solitary, summer-deciduous, dwarf geophyte to 10 mm in diameter. Roots fibrous. Tuber oblong, up to 35 × 10–15 mm, pale grey-brown and somewhat flaking, exposing the grey-green epidermis underneath; phyllopodia absent. Leaves softly succulent, apically produced, solitary or rarely with up to 3 leaves, ascending; blade irregularly molded, broadly club-shaped, orbicular to reniform (viewed from the top), often irregularly concave or shallowly grooved, 8–15 × 10–15 mm, cuneate and

The rough and the smooth: a reassessment of Conophytum reconditum

Summary: Recent field observations have given cause to re-examine one of the most enigmatic of all conophytum species, namely C. reconditum sensu lato. What follows chronicles a story over more than 25 years since its original description and in doing so describes the recent discovery of several hitherto unreported populations of the species. Their discovery has, in turn, led us to reevaluate the species and we now propose that C. reconditum subsp. buysianum is restored to specific level and a new subspecies is recognised in the form of C. buysianum subsp. politum subsp. nov.

Tylecodon bruynsii: a new cliff-dwelling species.

Tylecodons immediately draw your attention. Their thickset stems form perfect natural bonsai and are the main reason for their popularity. Nearly all of the 47 species in this genus of the stonecrop family (the Crassulaceae) are easy to grow, once you understand that these are winter growers that prefer to be dry and become deciduous for the long days of summer. But even in the heat of the dormant season, they confound the very idea of dormancy by putting on a show of attractive tubular flowers in brownish yellows, brick reds, fluorescent pinks, and soft to vivid greens. Tylecodons all originate from the semiarid to arid winter-rainfall southwestern portion of southern Africa, spanning the border between the Republic of South Africa and Namibia. The largest species is the widespread and impressive Botterboom (T. paniculatus), an Afrikaans name that describes its soft stems (botter = butter, boom = tree), an almost tree-sized desert dweller that can reach 3 m tall, with bark that peels in large yellow sheets. The smallest species, T. occultans, is a geophytic dwarf from the Knersvlakte region of southern Namaqualand. It’s just a few centimeters high and difficult to find among the quartz pebbles of its habitat.