keys to the vascular plants of east texas - Botanical Research ...

726 LILIACEAE
fronds originate); roots absent; flowers 1(–2) per frond, in cavity beside mid-line of upper surface
of frond, but plants seldom flowering; in quiet waters.
AA genus of 10 species (Landolt 2000), mostly of tropical and warm areas of the Americas
and Africa. The following key is based on non-flowering material because “Wolffiella fronds
change shape drastically when they are fertile …” (Godfrey & Wooten 1979). (Name a diminutive
of Wolffia)
REFERENCES: Landolt 1984; Crawford et al. 1997.
1. Fronds (4–)6–15(–20) times longer than wide, pointed at apex (= tip, the end opposite the end
where the daughter fronds originate), narrowly sabre-shaped, long-tapered from a slightly broader
base to the pointed apex; angle of vegetative reproductive pouch 25°–50° __________________ W. gladiata
1. Fronds 1.5-8 times longer than wide, rounded or pointed at apex, tongue-shaped to ribbon-like
or ovate, the sides � parallel for much of their length or short-tapered; angle of vegetative reproductive
pouch 45°–120°.
2. Area of air spaces in tissue near base of frond usually no longer than wide, occupying basal
1/3 to 1/2 of frond; fronds 1.5–4 times longer than wide, usually curved downward at apex;
angle of vegetative reproductive pouch 70°–120° ___________________________________ W. lingulata
2. Area of air spaces in tissue near base of frond usually longer than wide, occupying basal 2/3
or more of frond; fronds 3–8 times longer than wide, usually flat; angle of vegetative reproductive
pouch 45°–90° __________________________________________________________ W. oblonga
Wolffiella gladiata (Hegelm.) Hegelm., (sword-like), SWORD BOG-MAT. Fronds narrowly sabreshaped,
4–9 mm long, ca. 0.5–1.4 mm wide at base, distinctly long-tapered from a slightly
broader base to a pointed apex, often asymmetric near the apex with a curvature or an indentation
on one side, rarely solitary to usually 2–many (to 20 or more) attached, forming star-like
groups; area of air spaces within frond much longer than wide; seldom flowering. Scattered in
East TX; also Gulf Prairies and Marshes.; throughout most of the e U.S. w to IL and TX, also WA.
[Wolffia gladiata Hegelm., Wolffia gladiata var. floridana Donn. Sm., Wolffiella floridana (Donn.
Sm.) C.H. Thomps.]
Wolffiella lingulata (Hegelm.) Hegelm., (strap-shaped), TONGUE-SHAPED BOG-MAT. Fronds
tongue-shaped to widely so or ovate, 3–10 mm long, rounded at apex, � symmetric to strongly
curved, solitary to 2(–4) attached; seldom flowering. Harrison Co. (Evans & Brown 2002 based
on Nixon 16,133, ASTC); also Brazoria Co. (Turner et al. 2003); also Landolt (2000) mapped it for
the Gulf Prairies and Marshes just s of the Big Thicket; CA, FL, LA, MS, and TX. [Wolffia
lingulata Hegelm.]
Wolffiella oblonga (Phil.) Hegelm., (elliptical with blunt ends), SABER BOG-MAT. Fronds narrowly
tongue-shaped to ribbon-like, 1.2–7.5 mm long, rounded or pointed at apex, � symmetric near
the apex, solitary or 2–8 attached, forming star-like groups; seldom flowering. Jasper Co. (BRIT,
Diggs & George, s.n.—B.A. Steinhagen Lake, mixed collection with W. gladiata), also range map
in Landolt (2000) showing occurrence in s part of the Pineywoods (without specific county);
also Gulf Prairies and Marshes (Landolt 2000); CA, FL, LA, MS, and TX. [Lemna oblonga Phil.]
While not officially designated as such (e.g., TOES 1993; Carr 2002d; Poole et al. 2002), given its
limited distribution in the state, we consider this species to be of conservation concern in TX. �
LILIACEAE Juss.
LILY FAMILY
Perennial herbs from a bulb; leaves alternate or whorled along the stem or basal; flowers 1–few
in a terminal umbel-like cluster or solitary at end of a naked scape; flowers conspicuous; tepals
6, distinct, all petaloid; stamens 6; ovary superior, 3-carpellate; style 1; fruit a capsule.