The Collaborative International Dictionary of English v.0.48:

Marigold \Mar"i*gold\, n. [Mary + gold.] (Bot.)
   A name for several plants with golden yellow blossoms,
   especially the Calendula officinalis (see Calendula), and
   the cultivated species of Tagetes.
   [1913 Webster]

   Note: There are several yellow-flowered plants of different
         genera bearing this name; as, the African marigold or
         French marigold of the genus Tagetes, of which
         several species and many varieties are found in
         gardens. They are mostly strong-smelling herbs from
         South America and Mexico: bur marigold, of the genus
         Bidens; corn marigold, of the genus Chrysanthemum
         (Chrysanthemum segetum, a pest in the cornfields of
         Italy); fig marigold, of the genus
         Mesembryanthemum; marsh marigold, of the genus
         Caltha (Caltha palustris), commonly known in
         America as the cowslip. See Marsh Marigold.
         [1913 Webster]

   Marigold window. (Arch.) See Rose window, under Rose.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

African \Af"ri*can\, a. [L. Africus, Africanus, fr. Afer
   African.]
   Of or pertaining to Africa.
   [1913 Webster]

   African hemp, a fiber prepared from the leaves of the
      Sanseviera Guineensis, a plant found in Africa and
      India.

   African marigold, a tropical American plant (Tagetes
      erecta).

   African oak or African teak, a timber furnished by
      Oldfieldia Africana, used in ship building.
      [1913 Webster]

   African violet .

   African-American, see African-American.
      [1913 Webster]

WordNet (r) 3.0 (2006):

African marigold
    n 1: a stout branching annual with large yellow to orange flower
         heads; Mexico and Central America [syn: African marigold,
         big marigold, Aztec marigold, Tagetes erecta]