Polygonaceae

R. tuberosus L., Sp. PI. ed. 2, 481 (1762). Figure 7, p. 283.
Perennial, with at least some of the roots tuberous. Stems arcuate-ascending to erect, 10-60 cm. Lower leaves sagittate, acute or obtuse; stem leaves sagittate, usually acute. Inner perianth segments ± cordate-orbicular, 3-8 mm in diameter, much larger than the nut, tuberculate with small, backwardly directed tubercles. Outer perianth segments reflexed in fruit. A polymorphic species in which a number of subspecies are recognised (cf. Rechinger in Candoilea 12: 29-32,1949); four of these occur in Turkey:
1. Stems numerous, short, ascending; basal leaves very obtuse subsp. creticus
1. Stems usually single, tall, erect; basal leaves usually acute
  2. Inflorescence contracted; inner perianth segments c. 8 mm broad subsp. contractus
  2. Inflorescence not contracted; inner perianth segments 3-5 mm broad
   3. Inflorescence branches curving erect, themselves unbranched subsp. tuberosus
   3. Inflorescence branches straight, spreading, themselves branched subsp. horizontalis
subsp. horizontalis (Koch) Rech. in Candollea 12: 31 (1949). Syn: R. horizontalis Koch in Linnaea 22:211 (1849). Fl. 6-8. Banks, slopes, fields, scrub, 1750-2100 m.
Type: none cited.
A7 Gümüşane: Stadodopi, Sint. 1894: 6248! A8 Rize: Cimil valley, 2000 m, Bal. 419. A9 Kars: Sarikamiş, 2100 m, D. 32634! B6 Maraş: Binboğa Da., 1900 m, D. 20093! B7 Tunceli: S of Ovacik, 1750 m, D. 31559! B8 Erzurum: between Ilica and Tercan, 1900 m, D. 30910! C2 Antalya: Girdev G., 1800 m, D. 13764! Distribution of the species: S. Europe, N.W. Africa, Cyprus, S. Russia, Romania, Bulgaria, Caucasia, Syrian Desert, N. & N.W. Iran, Turkestan. The subspecies are often difficult to distinguish.