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

COMMELINA/COMMELINACEAE
491
4. Spathes not at all to slightly falcate, the margin usually ciliate near attachment to stalk;
false anthers of staminodes usually yellow with a central maroon/reddish brown spot; upper
cyme in spathes usually vestigial, not exserted (rarely well-developed, 1-flowered, and exserted);
capsules (5–)6–8 mm long; seeds of ventral locule 2.4–4.3(–4.6) mm long, smooth
to faintly alveolate; all 3 staminodes with well-developed false anthers ________________ C. caroliniana
Commelina caroliniana Walter, (of Carolina), CAROLINA DAYFLOWER. Stems decumbent to scandent;
leaf blades 7–15(–24) mm wide; leaf-like spathe enclosing flowers open both on the top
margin and also down the back margin to where it attaches to its stalk; petals all blue, one
slightly smaller and whitish medially; all 3 staminodes with well-developed false anthers,
these yellow, often with a central maroon spot. Fields, roadsides, and weedy areas; Colorado,
Harris, Orange, and Travis (Faden 1993) cos. on the s edge of East TX; also Gulf Prairies and
Marshes; se U.S. from NC s to FL w to AR, MO, and TX. Summer–fall. The species is apparently
native to India and Bangladesh (despite the specific epithet and common name) and was probably
introduced into the U.S. in South Carolina with rice seed in the late 17th century (Faden
1989). The characters used in the key to separate C. caroliniana from the similar C. diffusa are
modified from Faden (1989, 1993). I
Commelina communis L., (common), COMMON DAYFLOWER, ASIATIC DAYFLOWER. Stems erect, later
decumbent, to 4 mm in diam., to 50 cm tall; leaf blades (10–)15–40 mm wide; leaf-like spathe
enclosing flowers open both on the top margin and also down the back margin to where it attaches
to its stalk; all 3 staminodes with well-developed false anthers, these yellow, sometimes
with a central maroon spot. Stream banks and low thickets, sometimes a garden weed; Dallas
(BRIT), Brazos (TAMU), Gonzales, and San Jacinto (Turner et al. 2003) cos.; Faden (2000b)
mapped the species (without specific counties) as occurring in TX only in the n and ne parts of
East TX; Turner et al. (2003) also mapped two localities in the Gulf Prairies and Marshes; se
Canada and throughout e U.S. w to SD and TX, also OR. May–Oct. Native of e Asia. I
Commelina diffusa Burm. f., (diffuse, spreading), SPREADING DAYFLOWER, CREEPING DAYFLOWER,
CLIMBING DAYFLOWER. Stems erect initially, later decumbent, usually not more than 1.5 mm in
diam.; leaf blades 5–33 mm wide; leaf-like spathe enclosing flowers open both on the top margin
and also down the back margin to where it attaches to its stalk; only 2 of the 3 staminodes
with well-developed false anthers (1 staminode often lacking), these yellow, without a central
spot. Low woods; widespread in e 1/3 of TX w to Fannin (Talbot property), Rockwall (BRIT),
Gonzales, and Travis (Turner et al. 2003) cos.; e U.S. from VT s to FL w to KS and TX. Apr–Nov.
There is disagreement over the geographic origin of this species (Yatskievych 1999), which occurs
in tropical America, Asia, Africa, and the Pacific Islands; however, Faden (2000b) considers
it introduced to the U.S. This species is believed by some sources to be among the world’s worst
weeds (Holm et al. 1977). � I
Commelina erecta L., (erect), ERECT DAYFLOWER, HIERBA DE POLLO, WHITE-MOUTH DAYFLOWER.
Stems erect to decumbent, 10–70(–100+) cm long; leaf-like spathe enclosing flowers open on
the top margin but with edges fused together along the back margin; all 3 staminodes with
well-developed false anthers, these yellow, without a central spot. Native in various soils, often a
weed. May–Jun and Sep–Oct, occasionally Jul–Aug. While varieties are often distinguishable,
there is considerable variation (Brashier 1966) and overlap between them. Faden (2000b) indicated
the three varieties freely intergrade and are of questionable significance. m/282
1. Blades of middle and upper leaves broadly oblong-lanceolate, less than 5 times longer than
wide, 1.4–3.2 cm wide ______________________________________________________________ var. erecta
1. Blades of middle and upper leaves narrowly oblong-lanceolate or linear-lanceolate, more than 5
times longer than wide, 0.5–1.2(–2.0) cm wide.
2. Spathes (1.3–)1.5–2.0(–2.3) cm long ____________________________________________ var. angustifolia
2. Spathes (2.2–)2.5–2.8(–3.3) cm long ______________________________________________ var. deamiana