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

492 COMMELINACEAE/MURDANNIA
var. angustifolia (Michx.) Fernald, (narrow-leaved), NARROW-LEAF DAYFLOWER. In habitats as diverse
as sandy woods and rocky limestone slopes; throughout TX; throughout much of the U.S.
from PA s to FL w to WY and AZ.
var. deamiana Fernald, (for Charles C. Deam, 1865–1953, American botanist). Usually in sandy
soils; East TX w to Cross Timbers and Prairies (e.g., Hill Co.—BRIT); MI s to LA w to MN and AZ.
var. erecta. Thickets, stream banks or a weedy invader elsewhere; Madison (TAMU) and Dallas
(TAES) cos.; while we are aware of only a few TX sheets of this variety, it was reported from vegetational
areas 2, 4, 5, 6, 7, 8, and 9 by Hatch et al. (1990); e U.S. from NY s to FL w to AZ.
Commelina virginica L., (of Virginia), VIRGINIA DAYFLOWER. Plant spreading by elongate rhizomes;
stems coarse, 3–6 mm in diam. at base, usually strictly erect (rarely decumbent), to 90
(-100) cm tall; leaf blades scabrous when rubbed toward base; 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. Low woods, wet
places; Pineywoods and n Gulf Prairies and Marshes w to Blackland Prairie; the range map in
Faden (2000b) shows the species extending further w into the Cross Timbers and Prairies and
Edwards Plateau; e U.S. from N.J. s to FL w to KS and TX. May–Oct.
Commelina benghalensis L., (of Bengal), TROPICAL SPIDERWORT, BENGHAL DAYFLOWER, JIO, a common
paleotropical weed, has been discovered in several southeastern states (FL, GA, LA, NC) as
well as CA (Faden 1993; Thomas & Allen 1993; Faden 2000b; Krings et al. 2002). This species is
considered a noxious weed in FL, a U.S. federal noxious weed (Kartesz 1999; USDA Natural Resources
Conservation Service 2002), and according to sources to be among the world’s worst
weeds (Holm et al. 1977). It should be looked for in the moister parts of East TX adjacent to LA
and reported if found. It can be distinguished as follows: annual with relatively broad
unauricled leaves often with reddish hairs at sheath apex; leaf-like spathes with edges fused together
along the back margin, often clustered; corolla of three blue (–lilac) petals, one of these
smaller but still conspicuous; basal, sometimes subterranean cleistogamous flowers usually
present in addition to chasmogamous flowers (Krings et al. 2002). � I
MURDANNIA Royle DEWFLOWER
AA genus of ca. 50 species of pantropical and temperate areas (Faden 2000b). (Named for
Murdan Aly, plant collector and keeper of the herbarium at Saharunpore, India—Faden 2000b)
REFERENCES: Shinners 1962c; Faden 1978.
Murdannia nudiflora (L.) Brenan, (naked-flowered), NAKED-STEM DEWFLOWER. Annual herb to
35 cm tall; stems and branches often creeping and rooting at lower nodes; leaves sessile; leaf
blades linear to linear-lanceolate or lanceolate-oblong, 1.5–11(–18) cm long, 2–7(–8) mm wide;
inflorescences few-flowered cymes subtended by involucres of bracteoles that fall early, the
cymes terminating long peduncles (to 9+ cm long); spathaceous bracts absent; pedicels ca. 3
mm long, elongating to 4–5 mm in fruit; flowers bisexual, slightly bilaterally symmetrical; petals
3–3.5(–6) mm long, pinkish purple to purplish or violet, with expanded blades; fertile stamens
2, the filaments bearded; staminodes usually 4; capsules 3-locular, 2.5–5 mm long, with 2
seeds per locule. Roadsides and other weedy sites; Jefferson (BRIT) and Montgomery (TAES) cos.
near s margin of Pineywoods; also Gulf Prairies and Marshes; e U.S. from NC s to FL w to TX.
Summer–fall. Native of Asia. [Aneilema nudicaule (Burm. f.) G. Don, Aneilema nudiflorum (L.)
Sweet, Commelina nudiflora L.] A note on the Jefferson Co. sheet (Cory 49974, BRIT) said, “…a
pest and hard to eradicate from gardens.” This species is considered by some sources to be
among the world’s worst weeds (Holm et al. 1977). � I