Flowering Time Frame

• The forest floor covered in blooming trillium flowersHemera Technologies/Photos.com/Getty Images
  
  Trillium flowers bloom any time from March to May across North America. In more southern latitudes and at lower elevations, blooming begins by mid to late March. The farther north, nearer the Canadian border, flowering occurs more around early to mid May. The plants emerge from the leaf-covered forest floor looking like needled spears -- called scapes -- before unfurling their three green leaves, more accurately called bracts.
  
  

Flower Structure

• The flower's pistil may be three- or six-lobed.Hemera Technologies/Photos.com/Getty Images
  
  Although taxonomists today place trillium flowers in their own plant family, Trilliaceae, the group remains quite closely related to members of the larger lily family, Liliaceae. The flower, when open, resembles either a funnel or cup. Three green sepals occur just under the three petals, usually off-set so you can them all when viewing the face of the flower. When sepals and petals look similar in size, shape and color, botanists collectively refer to them all as six tepals. In the blossom center is a cluster of six stamens that shed pollen from their anther heads. Among the stamens is the female pistil that houses a three-chambered ovary.
  
  

Flowering Forms

• A pedicillate plant with partially erect flower.Hemera Technologies/Photos.com/Getty Images
  
  Scientists describe trillium flowers' overall plant and flowering form as being pedicellate or sessile. Pedicellate plants bear their blossoms on a pedicel, or stalk, that rises above the three leaf bracts. Pedicellate trinity flower blossoms may be held upright or horizontally, such as Trillium grandiflorium. Or, the blossom may droop or nod, facing the ground. The nodding flower may be held above the leaf bracts or hidden under them, such as with Trillium catesbaei. Sessile plants display the blossom directly atop the three bracts, making it look like the flower head has no neck. Examples include Trillium luteum and Trillium recurvatum.
  
  

Plant Reproduction

• Trillium flowers spread via seed and root offset production.Jupiterimages/Photos.com/Getty Images
  
  Ants, flies and beetles pollinate trillium flower blossoms. Pollination results in small fruits known botanically as a berry. The fruit drops to the ground and the flesh decomposes to reveal the seeds. The seeds germinate in the second spring if in contact with moist, humusy soil. Plants typically take five to seven years to reach a size when flowers form. Clumps of trillium flowers also arise from offsets formed by the underground rhizome roots.