Pterachaenia (Benth.) Stewart, Punjab Forest Rec. 2, 1 [Cat. Pl. Rawalpindi Distr.]: 50. 1952.

Zaika, Maxim A., Kilian, Norbert, Jones, Katy, Krinitsina, Anastasiya A., Nilova, Maya V., Speranskaya, Anna S. & Sukhorukov, Alexander P., 2020, Scorzonera sensu lato (Asteraceae, Cichorieae) - taxonomic reassessment in the light of new molecular phylogenetic and carpological analyses, PhytoKeys 137, pp. 1-85: 1

publication ID

http://dx.doi.org/10.3897/phytokeys.137.46544

persistent identifier

http://treatment.plazi.org/id/8BFED08C-C176-5B1A-8C15-61AA92B573DF

treatment provided by

PhytoKeys by Pensoft

scientific name

Pterachaenia (Benth.) Stewart, Punjab Forest Rec. 2, 1 [Cat. Pl. Rawalpindi Distr.]: 50. 1952.
status

 

Pterachaenia (Benth.) Stewart, Punjab Forest Rec. 2, 1 [Cat. Pl. Rawalpindi Distr.]: 50. 1952.  

Scorzonera sect. Pterachaenia   Benth. in Bentham & Hooker, Gen. Pl. 2: 532. 1873.Type: Pterachaenia stewartii   (Hook.f.) R.R.Stewart

Note.

Usually Lipschitz (1939: 31) is given as the place of publication for the generic name Pterachaenia   . His statement "I think this section will also turn out to be a separate genus (gen. proprium Pterachaenia   )" [translated from Russian] qualifies it, however, as a provisional genus name not formally accepted by its author.

Diagnostic features.

Flowering stems several or many, unbranched, leafless (scapes); phyllaries lanceolate, acute; florets yellow with red veins; achenes with 2-3 wings or without.

Description.

Habit, life form, subterranean parts: perennial with caudex or annual herbs, with taproot.

Leaves: rosulate, graminoid, linear or lanceolate, glabrous or hairy, often broadened in upper half.

Stem, synflorescence: stems leafless, unbranched (scapes) several to many, pubescent in lower part and glabrous in upper part, with terminal capitulum.

Pollen: echinolophate, tricolporate and each colpus divided into 2 lacunae, with 9 (6 abporal and 3 equatorial: P. stewartii   ) or 18 (6 abporal, 6 equatorial, 6 interporal: P. codringtonii   ) lacunae ( Blackmore 1982).

Capitula: involucre usually pubescent, phyllaries in two to several series, linear or lanceolate, acute, outer phyllaries 1/4-1/2 the length of the inner ones; receptacle glabrous, florets 12-22, yellow with red veins, equal in length to inner phyllaries.

Achenes: 12-15 mm, straight, without carpopodium; with 2-3 elongated ribs forming wings denticulate in upper part ( Pterachaenia stewartii   ) or without wings ( P. codringtonii   ), papillate and with small emergences (spinulae) ( P. stewartii   ) or with smooth surface ( P. codringtonii   ), with five principal ribs, parenchyma of two types, with thick-walled cells and with thin-walled cells, discontinuous (located above sclerenchyma between the principal ribs and below sclerenchyma in the rib areas) or only insular above sclerenchyma, air cavities absent, sclerenchyma continuous, equal in thickness, fibres orientated parallel to the fruit axis, tannins absent.

Pappus: 13-20 mm, fulvous, bristles plumose, apically scabrid.

Chromosome number.

x = 6 ( Pterachaenia stewartii   ) and x = 7 ( P. codringtonii   ), diploids.

Distribution area.

Asia-Temperate: AF; IR. Asia-Tropical: PK.

Species.

(1) Pterachaenia codringtonii   (Rech.f.) Zaika, Sukhor. & N.Kilian, comb. nov. ≡ Scorzonera codringtonii   Rech.f., Oesterr. Bot. Z. 97: 263. 1950. urn:lsid:ipni.org:names:77204061-1

(2) Pterachaenia stewartii   (Hook.f.) R.R.Stewart in Punjab Forest Rec. 2, 1: 50. 1952.

Kingdom

Plantae

Phylum

Tracheophyta

Class

Magnoliopsida

Order

Asterales

Family

Asteraceae

Loc

Pterachaenia (Benth.) Stewart, Punjab Forest Rec. 2, 1 [Cat. Pl. Rawalpindi Distr.]: 50. 1952.

Zaika, Maxim A., Kilian, Norbert, Jones, Katy, Krinitsina, Anastasiya A., Nilova, Maya V., Speranskaya, Anna S. & Sukhorukov, Alexander P. 2020
2020
Loc

Pterachaenia stewartii

R. R. Stewart 1952
1952