Biarum Schott

CATE Araceae, 17 Dec 2011. araceae.e-monocot.org

General Description

HABIT : seasonally dormant herbs, tuber subglobose, smooth. LEAVES : few to many. PETIOLE : often only weakly differentiated from blade, sheath long to short. BLADE : linear, oblong-lanceolate, oblong-ovate or -obovate, or elliptic-oblong, margins smooth to strongly crispate; primary lateral veins pinnate, ± forming submarginal collective vein, higher order venation reticulate. INFLORESCENCE : 1(-2) in each floral sympodium, usually appearing before leaves, rarely with or directly after the leaves at the end of the vegetative period. PEDUNCLE : short, usually hypogeal. SPATHE : constricted, erect, eventually evanescent, tube cylindric to ventricose, hypogeal or held just above ground surface, margins connate near base or for most of length, rarely margins free ( B. aleppicum), blade usually much longer, rarely shorter and reduced, expanded to gaping, linear to oblong-lanceolate or oblong, rarely campanulate or fornicate or subtriangular, usually dark brown-purple within, rarely white, pale yellowish or red-purple. SPADIX : shorter to much longer than spathe, female zone free, short, hemispheric to subhemispheric, subglobose, separated from male zone by rather long axis bearing sterile flowers at base or throughout or rarely naked, male zone 2-3 times longer than female, rarely with a short zone of sterile flowers above, appendix smooth, either ± slender, elongate-vermiform and not or hardly stipitate or thicker, cylindric to conoid and stipitate, rarely procurved and filiform, rarely with a short, basal zone of filiform processes. FLOWERS : unisexual, perigone absent. MALE FLOWER : 1-2-androus, anthers sessile, connective slender, apiculate and slightly prominent or not, thecae ellipsoid, with posterior microsporangia ± overtopping anterior ones, dehiscing by pore or lateral slit extending to the middle or nearly to the base and confluent apically. POLLEN : presented free or extruded in strands, grains inaperturate, spherical to subspheroidal, medium-sized (mean 30 µm., range 26-56 µm.), exine spinose or smooth. STERILE FLOWERS : consisting of either a single filiform, acute or subulate-conic projection, or rarely composed of 2-3 uncinate, recurved projections from a single receptacle. FEMALE FLOWER : ovary ovoid or oblong-ovoid, 1-locular, ovule 1, orthotropous, funicle very short, placenta basal, style very shortly conic to elongated, stigma subhemispheric. BERRY : obovoid, white to dull purple, pericarp carnose, not juicy, infructescence globose to hemispheric, borne at or slightly below soil level,. SEED : obovoid to subglobose, with obconic strophiole, testa smooth to irregularly rugose, thickish, embryo axile, more than half as long as endosperm, endosperm copious.

Habitat

Temperate and warm temperate scrub, woodland, open ground in fields, vineyards, pastures; geophytes, stony ground, under trees and shrubs, sandy areas, rarely on limestone, rock crevices.

Diagnostic

Seasonally dormant geophytes; leaves several, blades linear, oblong, oblong-lanceolate to ovate; lower spathe margins almost always connate (free in Biarum aleppicum); spadix normally with zone of sterile flowers between male and female zones; placenta basal. Differs from Eminium in having a 1-ovulate ovary and simple leaf blade.

Distribution

Portugal to Iran.