34. Raphanus L. (radish)
annual or biennial, terrestrial, usually sparsely pubescent with unbranched hairs.
Stems erect or ascending, usually branched. Leaves alternate and basal, nearly
all petiolate, the upper leaves progressively reduced, the bases not clasping
the stem, pinnately lobed or divided, the 5–15 lobes progressively
larger toward the leaf tip, the margins otherwise toothed or lobed.
Inflorescences panicles, the lower branches subtended by reduced leaves, the
flowers bractless. Sepals erect or ascending, narrowly oblong to oblanceolate
or nearly linear. Petals unlobed, purple, pink, white, or light yellow, with
dark purple veins. Stigma not lobed. Fruits more than 5 times as long as wide
or rarely less, ascending, straight or nearly so, circular in cross-section,
often corky in texture, segmented into apical and basal portions, the basal
portion relatively short, seedless, and stalklike, the apical portion 4 or more
times as long as the basal portion, tapering in the apical 1/4–1/2 to a
distinct, conical, seedless beak in addition to the style, indehiscent or
eventually breaking between the seeds into 1-seeded segments. Seeds in 1 row in
each locule, 2.0–3.5 mm long, oblong to nearly circular in outline, the
surface with a netlike or honeycomb-like pattern of ridges and pits, reddish
brown. Three species, Europe, Asia, Africa, introduced nearly worldwide.
fruits of Raphanus are unusual in that the seeds are effectively in a
single vertical rank and are immersed in corky tissue. Thus, there are no
locules in the mature fruit. The reduced basal segment usually contains
vestiges of the replum.