Eleocharis sect. Parvulae

T. V. Egorova in An. A. Fedorov

in An. A. Fedorov, Fl. Evr. Chasti SSSR 2: 110. 1976.

Treatment appears in FNA Volume 23.

Plants perennial; rhizomes creeping, 0.1–0.2 mm thick, soft, internodes to 4 cm, scales not evident, often terminating in a 2–4 mm tuber with large, acute, terminal bud, or tubers among culm bases. Culms terete, 2–9 cm × 0.2–0.5 mm, soft, spongy. Leaves: distal leaf-sheaths often disintegrating, thinly membranous, apex rounded. Spikelets: basal spikelets absent; proximal scale empty, amplexicaulous; floral scales membranous. Flowers: anthers 0.6–1.2 mm; styles 3-fid, rarely some 2-fid. Achenes trigonous, rarely some biconvex. Tubercles often rudimentary, often narrower than achene summit or sunken in a depression in achene, color and texture either similar to achene summit and tubercle merging with achene, or different and clearly distinct from achene.

Distribution

Temperate to tropical North America, Central America, South America, West Indies, Europe, North Africa

Discussion

Species 2 (2 in the flora).

Eleocharis sect. Parvulae is usually treated as monotypic. The taxonomy of its species should be carefully studied worldwide. H. K. Svenson (1957) grouped the species of sect. Parvulae with subg. Eleocharis (sect. Eleocharis) ser. Rostellatae and subg. Zinserlingia in E. ser. Pauciflorae (Beauverd) Svenson on the basis of the often poor differentiation between the tubercle and achene. DNA data presented by E. H. Roalson and E. A. Friar (2000) suggest that sect. Parvulae is closely related to 8a1. sect. Eleocharis.

Selected References

None.

"shortened" is not a number.

... more about "Eleocharis sect. Parvulae"
biconvex;trigonous +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
rounded +
S. Galen Smith* +, Jeremy J. Bruhl* +, M. Socorro González-Elizondo* +  and Francis J. Menapace* +
T. V. Egorova in An. A. Fedorov +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
persistent +
enlarged +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
2 cm20 mm <br />0.02 m <br /> (9 cm90 mm <br />0.09 m <br />) +
0.2mm;0.5mm +
Temperate to tropical North America +, Central America +, South America +, West Indies +, Europe +  and North Africa +
hypogynous +  and subtending +
biconvex +  and trigonous +
0 cm0 mm <br />0 m <br /> (4 cm40 mm <br />0.04 m <br />) +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
flattened +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
amplexicaulous +  and empty +
stramineous;medium brown or red brown or blackish brown +
in An. A. Fedorov, Fl. Evr. Chasti SSSR +
ascending +  and horizontal +
caudex-like +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
adventitious +
basal +  and proximal +
not evident +
2-keeled +
cylindric +
1 +  and 3 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
2-fid +  and 3-fid +
Eleocharis +
Eleocharis sect. Parvulae +
Eleocharis +
section +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
sunken +  and rudimentary +
often narrower +
stoloniferous +  and rhizomatous +