Trigonosciadium tuberosum Boiss., 1844

Eroğlu, Hüseyin, Behçet, Lütfi & Pinar, Süleyman Mesut, 2017, Taxonomic revision of the genus Trigonosciadium (Apiaceae) in Turkey, Phytotaxa 313 (1), pp. 43-60 : 46

1. Trigonosciadium tuberosum Boiss. in Ann. Sci. Nat., Bot. sér. 3, 1: 345 (1844) ( Figs 1 , 5–8 ).

Type:— [ IRAN?]. In Mesopotamia, Aucher 3723. Holotype: P ([digital image!] barcode number: P 00476419). Isotype: K ([digital image!] barcode number: K 000685757).

Synonym: Heracleum mesopotamicum M. Hiroe, Umbelliferae World : 1749 (1979), replacement name.

Biennial, herbaceous, 30–70 cm, pubescent, with petiole remains of last year at the base of the stem. Root swollen fusiform, 1–3(–5) paired. Stem erect, lower part 4–5 angular, striate, rarely purple. Leaves 1-pinnate, pilose, leaflets at the lower part of stem 7, middle 5, upper 3 paired, terminal leaflets single or slightly 3-lobed, margins serrate. Petiole sheath well-developed, in the lower part narrowly lanceolate, in the upper part ovate-oblong, widened and clasping the stem. Rays 7–30, 1–13 cm, unequal, pilose. Raylets 8–25, 4–18 mm, pilose. Bracts 1–5, 3–10 mm, linear-subulate, pilose. Bracteoles 2–4, 4–10 mm, linear, pilose, at least some of them longer than half of the pedicels in each umbellule. Sepals triangular, inconspicuous. Petals 5, white, deeply emarginate, pubescent at bottom and usually pinkish, the outer radiant, 4–5 mm. Styles ca. 3 mm, glabrous. Stylopodium cupular with undulate margin. Stigma capitate. Fruit 6–13× 5–10 mm, orbicular-obovate, obcordate, dorsal surface of mericarp hirsute and ± pilose, commissural surface of mericarp glabrous, mericarp margin usually undulate and purple; dorsal vittae 4, filiform, reaching 1/2–2/3 of mericarp; commissural vittae 2, filiform, reaching 2/3 of mericarp. Pollen grains in monads, tricolporate, perprolate ( P / E: 2.06); surface ornamentation rugulate.

Phenology:— Flowering occurs from May to June.

Distribution: — Turkey (Southeast of Turkey), Iran (Iranian Azerbaijan).

Habitat:— This species grows on stony, rocky valley slopes.

Threat category: —The latter Turkish collections of Trigonosciadium tuberosum were dated 1888 from C8 square, in Diyarbakır. During our study one of the population of this species was found also in Diyarbakır, but in C7 square. In accordance with our field observations, this population was distributed in 5–10 km 2 area and included approximately 300 mature individuals. According to the available data, it should be regarded as ‘Endangered’ [EN C2a(ii)] in Turkey.

Examined specimens:— C7 Diyarbakır: Bağlar, valley slopes on the Alaçimen Village , 37°44ʹ13ʺN, 39°55ʹ37ʺE, 1240 m, stony and rocky slopes, 5 May 2013, H. Eroğlu 1029 ( VANF!) ; ibidem, 25 May 2013, H. Eroğlu 1030 ( VANF!) .

Figures

FIGURE 1. Trigonosciadium tuberosum: A) habit; B) fruiting inflorescence; C) flower; D) dorsal surface of fruit; E) commissural surface of fruit; F) cross section of fruit.

FIGURE 5. Trigonosciadium tuberosum: A) general habit in nature; B) white flowers; C) pink bottom flowers; D) fruit. T. viscidulum: E) general habit in nature; F) flowers; G) undulate margin fruit; H) flat margin fruit. T. intermedium: I) general habit in nature; J) flowers; K) sepals; L) fruit. T. lasiocarpum: M) general habit in nature; N) flowers; O) lanate hairs on stem; P) fruit.

FIGURE 6. Distribution of Trigonosciadium species in Turkey: (▲) T. tuberosum, (□) T. viscidulum, (●) T, intermedium, () T. lasiocarpum.

FIGURE 7. SEM micrographs of pollen grains. Trigonosciadium tuberosum: A) polar view; B) ornamentation. T. viscidulum: C) polar view; D) ornamentation. T. intermedium: E) polar view; F) ornamentation. T. lasiocarpum: G) polar view; H) ornamentation.

FIGURE 8. Fruits of Trigonosciadium species. T. tuberosum: A) dorsal surface of fruit; B) commissural surface of fruit; C) SEM micrograph of fruit.T. viscidulum: D) dorsal surface of fruit; E) commissural surface of fruit; F) SEM micrograph of fruit. T. intermedium: G) dorsal surface of fruit; H) commissural surface of fruit; I) SEM micrograph of fruit. T. lasiocarpum: J) dorsal surface of fruit; K) commissural surface of fruit; L) SEM micrograph of fruit.