Scutellaria xylorrhiza Bornmüller (1911a: 7)

Salmaki, Yasaman & Müller, Jochen, 2019, Rediscovery of the enigmatic Scutellaria xylorrhiza (Scutellarioideae; Lamiaceae) - a rare endemic species from Iran, Phytotaxa 394 (4), pp. 267-275 : 272-274

Scutellaria xylorrhiza Bornmüller (1911a: 7) ( Figs. 1 , 2A‒B )

Type (Lectotype, designated here):—[ Iran] Kohrud, 20 June 1904, Th. Strauss s.n. ( JE 00001284!, isolectotype B 100241792!).

Plants perennial, saxicolous, suffruticose herbs with woody base. Stems thin and fragile, numerous, erect to decumbent, 4–10 cm tall, covered by papillate short simple hairs. Basal leaves long-petiolate; blade ovate to broadly ovate, 1.2‒2.2 × 1‒2.5 cm, subcrenate to entire, ± obtuse at apex, cuneate to rarely rounded at base, upper surface sparsely covered by short curved papillate simple hairs ( Fig. 3A ), lower surface rarely with peltate glandular hairs ( Fig. 3D ); petiole length equal or subequal to that of the blade. Cauline leaves shortly petiolate; blade broadly ovate to ovate-rounded, 1‒2 × 0.9‒2.1 cm, leaf margins and indumentum similar to the basal leaves (leaf margin sometimes dentate); petiole 1‒1.2 cm long. Inflorescence secund, compressed and terminal, dense, 4‒7 cm long, verticillasters 2-flowered. Bracts subsessile or with a short stalk (up to 1 mm long), ovate to lanceolate, 3‒4 mm long, covered by stalked glandular hairs and curved simple hairs. Pedicel 1‒2 mm long. Calyx 2‒3 mm long, growing to 5 mm in fruit, densely covered by exerted, long-stalked glandular hairs, sessile to subsessile peltate glandular hairs and curved papillate simple hairs ( Fig. 3B‒D ). Corolla 16‒20 mm long, tubular, apically bilabiate, with hooded upper lip, violet with a large white spot on lower lip, covered by stalked and sessile glandular hairs and simple short hairs outside, glabrous inside; corolla tube curved at base. Mericarps ovate to elliptic in outline, covered with appressed grey hairs, c. 1.3 × 0.8 mm.

Species examined: — Iran. Prov. Isfahan: south of Isfahan, N-facing slopes, Sofeh Mountains, 32°57′42″N, 51°64′65″E, ca. 1900 m, 1 August 2017, Y. Salmaki & S. Zarre 45417 ( TUH!), Y. Salmaki & S. Zarre 45418 ( TUH!).

Distribution and ecology: — Scutellaria xylorrhiza is found on bare rocks at N-facing slopes of the Sofeh Mountains south of Isfahan, a province capital in the central part of Iran ( Fig. 2C ). The small and cushion-forming subalpine species grows at an elevation of 1800–2200 m.

Phenology: —Flowering between late June and early August and fruiting between middle and late August.

Conservation remarks: — Scutellaria xylorrhiza can be considered as Critically Endangered (CR) subcategory A1 according to the IUCN Red List ( IUCN 2010) categories. It is known only from an area which is not very close to the type locality (Barzuk Mountain near Kohrud) in Isfahan Province. We found about 70 individuals of this plant in the single locality, but we presume there should be also populations in the type locality which are not easy to access. As there are no additional specimens except those that were collected by Strauss and Stapf in 1904, Jamzad (2012) considered this species as presumably extinct because the distribution area of this species is heavily disturbed by human usage.

Typification of Scutellaria xylorrhiza : —The name was published in the journal named Russkij Botaniceskij Zurnal ( Bornmüller 1911a), and in the same year, re-published in Beihefte zum Botanischen Centralblatt, Abteilung ( Bornmüller 1911b). Since the latter article addresses to the publication in Russkij Botaniceskij Zurnal, this may be considered as the protologue, although an earlier publication of the first is not proven.

The protologue ( Bornmüller 1911a) refers to a specimen from Kuh-i-Barsuk, collected on 22 June 1904 by Theodor Strauss, but without designation of that specimen as the holotype. No specimen with that collection date was found in the collections of B, JE and W, although W houses a specimen from Kuh Barsuk collected on 23 June 1904. Since this specimen has no original label, there might have been a transcription error. Another gathering at B and JE, labelled Kohrud, 20 June 1904, and cited by Bornmüller (1911b) should be regarded as an additional syntype. As Barsuk is in the district of Kohrud, Strauss may discarded to write the name on all sheets. We here select the sample (JE00001284) at JE as the lectotype and, the voucher specimen (B100241792) deposited at B as the isolectotype.

Figures

FIGURE 1. Lectotype of Scutellaria xylorrhiza (JE00001284).

FIGURE 2. (A, B) Scutellaria xylorrhiza in its natural habitat, (C) distribution map of S. xylorrhiza in Iran.

FIGURE 3. Scanning electron micrographs of leaf and calyx of Scutellaria xylorrhiza. A: leaf; B‒D: calyx.