Zea mays

HABIT Annual. Culms erect; 200–300 cm long; with prop roots. Culm-internodes solid. Leaves cauline. Ligule an eciliate membrane. Leaf-blades linear, or lanceolate; 25–100 cm long; 20–100 mm wide.

INFLORESCENCE Monoecious; with male and female spikelets in different inflorescences. Inflorescence composed of racemes; axillary; subtended by a spatheole; enclosed. Spatheole elliptic; herbaceous.

Racemes 1; single; multilateral. Rhachis enlarged into a woody cob. Spikelet packing crowded; regular; 4–11 -rowed.

Spikelets sunken; in pairs. Fertile spikelets sessile; 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets obovate; dorsally compressed; persistent on plant.

GLUMES Glumes similar; reaching apex of florets; firmer than fertile lemma. Lower glume oblate; 1 length of spikelet; scarious; of similar consistency above; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume margins ciliate. Upper glume oblate; scarious; of similar consistency above; without keels; 0 -veined. Upper glume lateral veins absent. Upper glume margins ciliate.

FLORETS Basal sterile florets barren; with palea, or without significant palea. Lemma of lower sterile floret ovate; membranous; 0 -veined; without midvein; without lateral veins. Fertile florets female. Fertile lemma orbicular; membranous; without keel; 0 -veined.

FLOWER Lodicules absent (female), or 2 (male). Anthers 3. Stigmas 2; terminally exserted; papillose. Styles connate below.

FRUIT Caryopsis with adherent pericarp; exposed between gaping lemma and palea at maturity.

MALE Male inflorescence terminal; unlike female; of racemes along a central axis. Male spikelets distinct from female. Male spikelet glumes 2; wingless; muticous. Male spikelet lemma 3–5 -veined; muticous.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, and western Indian ocean. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, Arabia, China, and eastern Asia. Asia-tropical: India, Indo-China, Malesia, and Papuasia. Australasia: Australia. Pacific: southwestern, south-central, northwestern, and north-central. North America: northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, southeast USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Andropogoneae. FTA.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.