Lactuca georgica Grossh.

Nomenclature
The Plant List Lactuca georgica Grossh.
GRIN Taxonomy Lactuca georgica Grossh.
Cichorieae Portal Lactuca georgica Grossh.
Tropicos Lactuca georgica Grossh.
Euro+Med Plantbase Lactuca georgica Grossh.


Native distribution
Asia Armenia; Azerbaijan; Georgia; Iran; Russian Federation; Turkey; Turkmenistan


Key features
Lettuce gene pool Primary relative
Chromosome number 2n = 18
Habitat Roadsides
Life history Biennial; perennial
Breeding system Autogamous
Flower colour Yellow
EURISCO (Dec. 2017) 23 accessions


Morphological description
Plant Height 75-150 cm with a robust tap root
Stem Mostly solitary, glabrous or with sparse, stiff, spinules below, sulcate, fistular, branched above
Leaves Stiff, semiamplexicaul, elliptical (except upper leaves), ovate or oblong, with prominent network of veins beneath, often toothed-spinose. Lower leaves almost entire or cut to various degrees, basally narrowed into broad-winged petiole, covered with stiff, about 2 mm long, spinules along midrib beneath. Middle leaves usually pinnatisect, gradually reduced upward, often with isolated spiriules beneath along midrib. Upper leaves small, variable in form, mostly triangular with deeply emarginate base and auriculate appendages
Inflorescence Paniculate or racemose, often robust
Heads Cylindrical, with fruits 8-11 mm long, with about 15 florets, borne singly or in groups of few, almost sessile or, less often on more or less long peduncles. Involucre usually four-rowed. Outer involucral bracts thinly and densely tomentose (and also glandular?), often violet. Inner ones less densely pubescent, with subobtuse, often violet apex, and mostly with distinct midrib. Corolla yellow
Achenes Dark violet or almost black, somewhat flattened or flat, 6-7 mm long, broad obovoid part up to 3-3.5 mm long (about 1.5 mm wide), abruptly narrowed at apex into narrow, about 1 mm long, collar bearing light-colored or dark brownish, filiform, 2.0-2.5 mm-long beak, with prominent ribs (usually seven) on each side covered with numerous light-colored stiff, short, upward-directed hairs (under a hand lens!). Besides, achenes covered with very short, transversely sinuate, stripes of short light-colored hairs (under high magnification!). Beak terminating in small funnel-shaped expansion bearing flat disk with pappus of thin, silky, almost smooth, fragile, 3.0-3.5 mm-long hairs
Reference Cichorieae Portal - based on Bobrov E.G. & Tzvelev N.N. (2000) Flora of the USSR XXIX, Compositae, Tribe Cichorieae. Enfield