Namaquanthus cephalophylloides Klak 2001, sp. nov.
Creators: name: Klak, Cornelia
name: Hanáček, Pavel
name: Bruyns, Peter V.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Caryophyllales
Aizoaceae
Namaquanthus
Namaquanthus cephalophylloides

description: <b> 2. <i>Namaquanthus cephalophylloides</i> Klak</b> <b>sp. nov.</b> (Fig. 5) Type: South Africa, Northern Cape, Kwaganap River, between Port Nolloth and Grootmis (2917 AC), 19 Jul. 2021, 150 m, <i>Klak 2917</i> (BOL, holo.). Differs from <i>N. vanheerdei</i> by its much smaller stature (to 10 cm tall as opposed to 30 cm tall in <i>N. vanheerdei</i>). In addition, the stalks of maturing fruit bend downwards and the fruit finally detach from the plant along a preformed incision, whereas the fruit remain erect and attached to the fruit-stalk in <i>N. vanheerdei</i>. Dwarf, clump forming more or less stemless perennial succulent, with only basal part very woody, &lt;10 × 15 cm. <i>Leaves</i> opposite, ascending, ± free to their bases, finger-shaped, with upper side only slightly flattened, 45–60 × 8–13 mm, tips obtuse. <i>Flowers</i> solitary, 45–50 mm diam., pedicels erect to slightly bent, bending further down as fruit matures, to 45 mm long, bracts succulent and positioned near the base of plant and thus hidden between the leaves; sepals 4, subequal, succulent, flat and broad, ± 8.5 × 8.2 mm, 2 slightly narrower to 5 mm broad and with membranous margins; petaloid staminodes brilliant magenta, paler towards the center, 2- to 3-seriate, ± same length, 22–24 × 2.8 mm, lanceolate to obtuse, filamentous staminodes absent; stamens numerous, filaments 3.5–5.2 mm long, inner ones shortest, white, papillate at base, in 3–4 rows, pollen white; stigmas 8–9, short, feathery, 2.5 mm long, yellowish, top of ovary slightly raised in the center; nectary forming green, crenulated ring. <i>Capsule</i> 8- to 9-locular, detaching from pedicel once mature, 10 mm diam., top raised to 3 mm, with low rims, lower part 7 mm deep, rounded to bell-shaped, basally indented where pedicel attached, covering membranes thin and flexible, raised in the center, without additional closing-devices below, completely covering the locules, without closing-bodies, valve wings broad, ± rectangular. <i>Seeds</i> ochre, to 1.1 mm long, echinate with slender papillae. <b>DISTRIBUTION AND ECOLOGY</b> The species is only known from the Kwaganap River south-east of Port Nolloth, in the arid winterrainfall region of northern Namaqualand (Fig. 4). Here it occurs on shallow loamy soils overlaying gneiss with quartz-gravel on the surface. The species occurs at an altitude of around 150 m. It flowers between May and July. The similarly restricted <i>N. vanheerdei</i> is only known from north- and westfacing quartzitic slopes around 30 km east of Port Nolloth (Fig. 4). <b>DISTINGUISHING FEATURES AND RELATIONSHIPS</b> <i>N. vanheerdei</i> forms shrubs to 30 cm high and to 50 cm diameter, whereas <i>N. cephalophylloides</i> is a clump-forming dwarf shrub that does not exceed 15 cm broad. Both species of <i>Namaquanthus</i> have thick, finger-shaped leaves that are more or less free to their bases. However, in the new species the leaves are gray, almost white from a thick covering of wax, whereas <i>N. vanheerdei</i> has dark green leaves, which are typically partially blackened by a fungus or a lichen in their habitat (Fig. 2 B). Furthermore, both species possess large bril- liantly colored, magenta, solitary flowers. However, the pedicels are erect and only reach 10 mm long in <i>N. vanheerdei</i> (Fig. 2), whereas they are to 45 mm long and curved in <i>N. cephalophylloides</i> (Fig. 5 B). Unusual for <i>N. vanheerdei</i> is that the inner petals unfold only after several days, hiding the center of the flower in the beginning (Fig. 2 C, D). Such slow opening of the flowers was not observed for <i>N. cephalophylloides</i>. Bolus (1954) reported the anthers and pollen to be deep purple for <i>N. vanheerdei</i>. However, our own observations revealed that some plants can also have yellow pollen (Fig. 2 C), whereas the pollen is white in <i>N. cephalophylloides</i>. Noteworthy are the echinate seeds (Fig. 5 E, F), which are common to both species. Unusual in <i>N. cephalophylloides</i> are the downward pointing fruits (Fig. 5 A), which become detached once they are mature. This contrasts with most of the species in the Ruschioideae, where the fruits are retained on the plant for 1–2 years or longer. In <i>Cephalophyllum</i>, the tops of the fruits always point upwards and possess closing-bodies. Although papillate seeds are also found in <i>Astridia</i>, the fruits of <i>Astridia</i> have closing-bodies, which are absent in <i>Namaquanthus</i>. A possible close relative is the monotypic <i>Enarganthe</i>, which differs in its trigonous to clubshaped leaves and the pear-shaped, elongated, almost smooth seeds. <b>ETYMOLOGY</b> The epithet refers to the superficial resemblance of the new species to members of <i>Cephalophyllum</i>. <b>CONSERVATION STATUS</b> We consider this species to be rare, because of its specific habitat requirements. These are large patches of quartz-gravel close to the sea. A similar habitat at Grootmis near Kleinzee, did not contain this species. This contrasts with <i>Drosanthemopsis kwaganapensis</i> Klak, which is found at the type locality of <i>N. cephalophylloides</i> and also at Grootmis (Klak et al. 2018). Given the isolat- ed nature and the high habitat-specificity of the known population, we recommend that it is considered Vulnerable and placed on the Red Data List of South African plants.
description: Published as part of <i>Klak, Cornelia, Hanáček, Pavel &amp; Bruyns, Peter V., 2023, Two New Species of Aizoaceae (Ruschieae, Ruschoideae) from the Cape, South Africa., pp. 16-23 in Haseltonia 29 (1)</i> on pages 21-22, DOI: 10.2985/026.029.0103, http://zenodo.org/record/7877317
description: {"references": ["Bolus, H. M. L. 1954. Namaquanthus vanheerdei. Notes on Mesembryanthemum [H. M. L. Bolus] 3: 257 - 258.", "Klak, C., P. Hanacek and P. V. Bruyns. 2018. A recircumscription of Jacobsenia (Aizoaceae): Re-instating Drosanthemopsis, with two new quartz-endemics from Namaqualand, South Africa and sinking Knersia. South African Journal of Botany 116: 67 - 81."]}