Isatis is a genus of flowering plants in the family Brassicaceae, native to the Mediterranean region east to central Asia. Its genus name, Isatis, derives from the ancient Greek word for the plant, ἰσάτις. The genus includes woad (Isatis tinctoria). Due to their extremely variable morphology, the Asian species in particular are difficult to determine; the only reliable diagnostic feature is the ripe fruit. They are (usually) biennial or perennial herbaceous plants, often bluish and hairless or downy hairy with the upright stem branched.H. Moazzeni et al .: Phylogeny of Isatis (Brassicaceae) and allied genera based on ITS sequences of nuclear ribosomal DNA and morphological characters. In: Flora (Elsevier), Volume 205, 2010, pp. 337–343.
Description They are annual, biennial or perennial, branched herbs, usually glabrous and glaucous except silique. Basal leaves generally elliptic-oblong, sessile; sessile caulinary, rounded to oval-oblong.
The hermaphrodite flowers are fourfold double perianth. The four sepals are ascending to upright. The four yellow to off-white or lilac-white petals are at least as long as the sepals. They have six stamens with very small, egg-shaped or elongated-round anthers. There are nectar glands. Racemose is branched or paniculated, ebracted, inflorescence, often reaching lax and elongated in the fruit.
The fruit is a generally linear silique, oblong-cuneate to suborbicular, indehiscent, flattened laterally, unilocular, little to conspicuously winged, glabrous or with tiny hairs.Flora of North America Editorial Committee, e. 2010. Magnoliophyta: Salicaceae to Brassicaceae. Fl. N. Amer. 7: i – xxii, 1–797.
Species Currently accepted species include:
Isatis afghanica Hadac & Chrtek Isatis amani P.H.Davis Isatis apennina Ten. ex Grande Isatis apscheronica N.Busch Isatis aptera (Boiss. & Heldr.) Al-Shehbaz, Moazzeni & Mumm. Isatis arenaria Azn. Isatis armena L. Isatis arnoldiana N.Busch Isatis aucheri Boiss. Isatis biscutellifolia Boiss. & Buhse Isatis bitlisica P.H.Davis Isatis boissieriana Rchb.f. Isatis brachycarpa C.A.Mey. Isatis brevipes (Bunge) Jafri Isatis bullata Aitch. & Hemsl. Isatis bungeana Seidlitz Isatis buschiana Schischk. Isatis callifera Boiss. & Balansa Isatis campylocarpa Boiss. Isatis canaliculata (Vassilcz.) V.V.Botschantz. Isatis candolleana Boiss. Isatis cappadocica Desv. Isatis cardiocarpa (Trautv.) Al-Shehbaz, Moazzeni & Mumm. Isatis caucasica N.Busch Isatis cochlearis Boiss. Isatis constricta P.H.Davis Isatis costata C.A.Mey. Isatis davisiana H.Misirdali ex P.H.Davis, R.R.Mill & Kit Tan Isatis demiriziana H.Misirdali ex P.H.Davis, R.R.Mill & Kit Tan Isatis densiflora (Bunge ex Boiss.) D.A.German Isatis deserti (N.Busch) V.V.Botschantz. Isatis djurjaedae Coss. & Durieu Isatis elegans (Boiss.) Hadac & Chrtek Isatis emarginata Kar. & Kir. Isatis erzurumica P.H.Davis Isatis floribunda Boiss. ex Bornm. Isatis frigida Boiss. & Kotschy Isatis frutescens Kar. & Kir. Isatis gaubae Bornm. Isatis glastifolia (Fisch. & C.A.Mey.) Al-Shehbaz, Moazzeni & Mumm. Isatis glauca Aucher ex Boiss. Isatis grammotis Kit Tan Isatis gymnocarpa (Fisch. ex DC.) Al-Shehbaz, Moazzeni & Mumm. Isatis harsukhii O.E.Schulz Isatis hirtocalyx Franch. Isatis huber-morathii P.H.Davis Isatis iberica Steven Isatis jacutensis (N.Busch) N.Busch Isatis karjaginii Schischk. Isatis kotschyana Boiss. & Hohen. Isatis kozlovskyi Grossh. Isatis laevigata Trautv. Isatis latisiliqua Steven Isatis leuconeura Boiss. & Buhse Isatis littoralis Steven Isatis lockmanniana Kotschy ex Boiss. Isatis lusitanica L. Isatis mardinensis P.H.Davis & H.Misirdali Isatis maxima Pavlov Isatis microcarpa J.Gay ex Boiss. Isatis minima Bunge Isatis multicaulis (Kar. & Kir.) Jafri Isatis oblongata DC. Isatis odontogera (Bordz.) D.A.German Isatis ornithorhynchus N.Busch Isatis pachycarpa Rech.f., Aellen & Esfand. Isatis pinnatiloba P.H.Davis Isatis platyloba Link ex Steud. Isatis praecox Kit. ex Tratt. Isatis raimondoi Di Grist., Scafidi & Domina Isatis raphanifolia Boiss. Isatis rugulosa Bunge ex Boiss. Isatis sabulosa Steven ex Ledeb. Isatis sevangensis N.Busch Isatis sivasica P.H.Davis Isatis spatella P.H.Davis Isatis spectabilis P.H.Davis Isatis steveniana Trautv. Isatis stocksii Boiss. Isatis subdidyma (N.Busch) V.E.Avet. Isatis takhtajanii Avet. Isatis tinctoria L. Isatis tomentella Boiss. & Balansa Isatis trachycarpa Trautv. Isatis turcomanica Korsh. Isatis undulata Aucher ex Boiss. Isatis violascens Bunge Isatis zarrei Al-Shehbaz, Moazzeni & Mumm.
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