Acantholimon assadii Mirtadz. & Bordbar, 2022

Bordbar, Firouzeh & Mirtadzadini, Mansour, 2022, Acantholimon assadii (Plumbaginaceae), a new species from flora of Iran, Phytotaxa 574 (1), pp. 99-104 : 100-103

Acantholimon assadii Mirtadz. & Bordbar , sp. nov.

( Figs. 1 and 2 )

Type:— IRAN. SE, N of Kerman Prov.: Zarend, between Rigabad and Dārbidkhun, N30°45’52.21”, E56°46’27.98”, 2180 m, 26.VIII.2011, Mirtadzadini 3850 (holotype and isotypes: MIR!)

Other specimen examined:— IRAN. Southeast, N of Kerman Prov.: N of Kerman, Zarend, between Rigabad and Dārbidkhun, N30°45’52.21”, E56°46’27.98”, 2180 m, 02.VII.2007, Mirtadzadini 3851 ( MIR!). Zarend , west cliffs of Hotkan , N30°50’47”, E56°46’49.5”, 2355 m, 09.IX.2020, Mirtadzadini and Bordbar 3852 ( MIR!) .

Diagnosis: —Differs from Acantholimon cabulicum , A. kermanense and A. mirtadzadinii by the bract on peduncle ovate-triangular, the bract on peduncle 4–7 mm long, the bract of spikelet ovate-triangular, terminating to a mucron up to 2.5 mm long, the bract of spikelet ca. 6 mm long, the bracteoles narrow obovate-oblong, with rounded or more or less emarginated apex, the calyx pale brown to fuscous.

Description:—Plant frutescent (woody at the base), caespitose, ca. 30–40 cm broad in diameter, pulvinate, heterophyllous, glabrous except for the sheath of leaves. Leaves bright green, spring leaves persistent, rather flat, narrowly lanceolate, 10–15 mm × 3 mm, entire at the margin, summer leaves 25–35(–40) mm × 2.5 mm, spiny. Flowering stem (peduncle) 7–12 mm, not exceeding the leaves, peduncle bearing one bract, bract 4–7 mm, narrow triangular, long acuminate, terminating to a short spine. Inflorescence 20–40 mm, densely spicate, rarely branched, with 5–8 spikelets, spikelet 1–3 flowered. Bract ca. 6 mm long and ca. 3.3 mm wide, ovate-triangular, with a hyaline margin ca. 0.3–0.5 mm wide, terminating to a mucron up to 2.5 mm long, green or green-purple. Bracteoles 4–6, unequal, 6–9 mm long, 2.2–3 mm wide, narrow obovate-oblong, with rounded or more or less emarginated apex, with or without short mucron up to 0.3 mm, with a wide hyaline margin ca. 0.5–1 mm wide, green-purple. Calyx infundibularis, glabrous inside, pale brown to fuscous, ca. 10 mm long, tube ca. 6 mm, blade ca. 4 mm long and 5–6 mm wide, with fuscous veins not exceeded the blade margin. Corolla white, 12–14 mm long. Filaments slightly longer than the styles, 12–14 mm, anthers 0.7 × 0.4 mm, pale pink.

Etymology: —The species is named in honor of Prof. Mostafa Assadi, an Iranian taxonomist for his worthy studies on Acantholimon .

Phenology:—Flowering time mid-July to mid-September, fruiting time September-October.

Distribution, habitat and conservation status:—The distribution area of the new species in N of Kerman is a part of the Irano-Turanian floristic region. During field observations, only three mature individuals of the new species were counted in two locations 10 km apart distributed in mountainous slopes. Because of its extremely narrow geographical distribution, it needs support for conservation. However, any statement using standard criteria about the level of support for conservation needs to further explorations. Acantholimon assadii is a spiny and dense shrub that makes it capable to be resistant against the herbivorous animals. But this plant might be burned as a fuel source by local people due to its narrow, dens and flammable branches.

Taxonomic remarks:—By having heteromorphous leaves, permanent spring leaves, spike-like inflorescence, spikelet with 1–3 flowers and 4–6 bracteoles, and glabrous inside infundibularis calyx, the new species belongs to sect. Acantholimon . A. assadii has densely spicate inflorescence similar to that of A. cabulicum distributed in NE, NW and C of Afghanistan ( Fig. 3 ). However, they differ mainly in characteristics of bract, bracteole and calyx ( Table 1 ). A. assadii is completely distinctive in the features of inflorescence, bract, bracteole, calyx and corolla from the other Iranian species belonging to the sect. Acantholimon . This species is geographically closer to the two species of sect. Acantholimon namely A. mirtadzadinii Assadi (2003: 28) and A. kermanense Assadi & Mirtadz. (2006: 130) from W of Kerman Province ( Fig. 4 ). A. assadii is easily distinguished from A. mirtadzadinii and A. kermanense by the color of calyx: pale brown to fuscous in A. assadii versus dark purple in A. mirtadzadinii and dark purple or purple in A. kermanense . The corolla is white in A. assadii while it is pink to purple in A. mirtadzadinii and A. kermanense . They also differ in the shape and length of bract on peduncle, shape and length of bract of spikelet and shape of bracteoles ( Table 1 ).

Figures

FIGURE 1. Acantholimon assadii from its type locality. A) Habit and habitat; B) close-up view of spikelets.

FIGURE 2. Line drawing of spikelet bract and bracteoles (left to right) in Acantholimon assadii. Scale bar = 2 mm.

FIGURE 3. Type specimen of Acantholimon cabulicum (K000704396).

FIGURE 4. Acantholimon species from sect. Acantholimon distributed in south-east of Iran. A) A. mirtadzadinii, B) A. kermanense.