An Illustrated Flora of the Northern United States, Canada and the British Possessions/Marantaceae

Family 30.   Marantàceae   Lindl.   Nat. Syst.   1830.
Arrowroot Family.

Tall herbs, perennial by rootstocks or tubers, or sometimes annual, with scapose or leafy stems, mostly large entire long-petioled sheathing leaves, often swollen at the base of the blade, the veins pinnate, parallel.  Flowers perfect or sometimes polygamous, irregular, in panicles, racemes or spikes.  Perianth superior, its segments distinct to the summit of the ovary or united into a tube, normally in 2 series of 3, the outer (sepals) usually different from the inner (petals).  Perfect stamen 1; anthers 1-2-celled.  Staminodia mostly 5, often petal-like, separate or united by their bases, very irregular.  Ovary 1-3-celled, inferior; ovule 1 in each cavity, anatropous; style slender, curved, terminal; stigma simple.  Fruit capsular or berry-like, 1-3-celled.  Seed solitary in each cavity.  Embryo central, in copious endosperm.

About 12 genera and 160 species, mostly in the tropics, a few in warm-temperate regions.

1.   Thàlia   L.   Sp. Pl. 1193.   1753.

Annual (or perennial?) herbs, with large long-petioled basal leaves, erect simple scapes and terminal panicled spikes of bracted usually purple flowers.  Sepals 3, membranous, separate, equal.  Petals 3, separate or somewhat coherent at the base.  Staminodia slightly united below, one of them (labellum) broad, crested.  Anther 1-celled.  Ovary 1-celled or with 2 additional small empty cavities.  Base of the style adnate to the base of the stamen-tube.  Stigma 2-lipped, dorsally appendaged.  Capsule globose or ovoid.  Seed erect.  Embryo strongly curved.  [In honor of Johann Thalius, German naturalist of the sixteenth century.]

About 7 species, all American.  Besides the following, another occurs in the southern States.  Type species: Thalia geniculata L.