The Neotropical genus Taccarum was described by Schott (1857) and the last complete revision was done by Engler (1920). Since then, the genus has not been revised, although it was broadly surveyed by Bogner (1989). During the preparation of the complete revision of the tribe Spathicarpeae it was possible to compare type specimens and cultivated material of all known species of Taccarum: this revision is now in preparation (Goncalves, in prep.). One of the most poorly known species of the genus - Taccarum warmingii - was described by Engler in 1880 based on the material collected by the Danish naturalist Eugene Warming during his stay in Lagoa Santa, Minas Gerais state, Southeastern Brazil. After the original collection, a second gathering from Minas Gerais was sent to England by the horticulturist W. Bull and redescribed in flower by Brown (1881). This material seems to have been lost in subsequent years. Only a few poorly documented specimens were discovered during the 20th Century, all very far from the type locality, including a collection from Rio de Janeiro state. All of these remained misidentified for many years in Brazilian herbaria, and the real identity of T. warmingii remained obscure. In the second half of the 20th Century, the naturalist Roberto Kautsky found a population of a terrestrial tuberous aroid in. Espirito Santo state, near the village Santa Leopoldina, in a locality called "Sao Paulo". The area is already known for being the only place were the horticulturally illustrious species Philodendron spiritus-sancti can be found (Goncalves & Salviani, 2001). Propagules of this tuberous species were brought by Mr. Kautsky to his collection in Domingos Martins, and cultivated for years. In 2000, samples of this collection, including a flowering specimen, were sent to me. Until it was possible to analyze the original description and type specimen of T. warmingii, this material from Espirito Santo was supposed to be a new species because of its unexpected robustness and its distinctive features. One of these living samples flowered once again in cultivation at Instituto Plantarum in 2001. Unfortunately, it was not possible to obtain a second inflorescence in order to try a manual pollination and observe fruits. However, the amount of information amassed is now enough to prepare a new description of this elusive species.
HABIT : seasonally dormant herbs, often robust, tuber depressed-globose. LEAF : solitary. PETIOLE : terete, mottled and variegated or not, sheath very short. BLADE : juvenile leaves simply lobed, adult leaves trifid to trisect, anterior division usually deeply bipinnatifid, often tripinnatifid in lower pinnae, posterior divisions deeply pedatifid with segments themselves pinnatifid, ultimate lobes subtriangular to elliptic or lanceolate, acute to acuminate, broadly decurrent; basal ribs well-developed, primary lateral veins of ultimate lobes pinnate, running into inconspicuous marginal vein, higher order venation reticulate. INFLORESCENCE : 1, rarely 2 in each floral sympodium. PEDUNCLE : usually much shorter than petiole. SPATHE : not constricted, tube convolute, blade gaping to widely spreading, marcescent and later deciduous (T. weddellianum). SPADIX : free or female zone adnate to spathe, sessile or stipitate, erect, much longer than, subequal to or shorter than spathe, male zone usually contiguous with female, rarely with a few bisexual flowers in between, fertile to apex. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-8-androus, stamens connate, synandrium very long-stipitate with apical whorl of anthers to short with anthers near base, stigmatoid apex inconspicuous or distinct and 4-6-lobed, or very large and dome-shaped, thecae oblong or broadly ellipsoid, dehiscing by short apical slit or pore. POLLEN : extruded in strands, inaperturate, ellipsoid to oblong, large (mean 63 µm., range 49-76 µm.), exine scabrate or verruculate or spinulose-spinose, or smooth (psilate). FEMALE FLOWER : gynoecium surrounded by whorl of 4-6 free, erect, filiform, clavate or oblong, often flattened staminodes, or by urceolate synandrode composed of connate staminodes (T. caudatum), ovary 3-6(-7)-locular, ovules 1 per locule, anatropous, funicle short, placenta axile, style very long and slender or very short to ± absent, always narrower than ovary, stigma thick, capitate or 5-7-lobed, lobes erect or stellate. BERRY : borne in cylindric infructescence, depressed-globose, slightly furrowed, style persistent, 3-5-seeded, . SEED : ellipsoid, raphe conspicuous, testa granulate, light brown, embryo straight, elongate, endosperm copious.
Often robust, seasonally dormant, tuberous geophytes; leaf solitary; leaf blade dracontioid, ultimate lobes lacking submarginal collective veins, fine venation reticulate; spadix fertile to apex, male and female zones usually contiguous; flowers unisexual, perigone absent; male flower a stipitate synandrium; female flower with a whorl of free or connate staminodes. Differs from Asterostigma in having leaf blades subdracontioid to dracontioid, synandria elongate, stigma capitate or with rounded lobes (lobes star- or cross-like in Asterostigma).