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

522 CYPERACEAE/CAREX
45. Larger perigynia (4.7–)5–5.5 mm long; larger pistillate
scales acuminate, (3.8–)4–4.9 mm long, 3.3–4.2 times
longer than wide; achenes (1.2–)1.3–1.6 times longer
than wide _____________________________________ C. shinnersii
37. Perigynia veinless or rarely with 1–3 faint veins over the achene on the
adaxial (= ventral) surface.
46. Perigynia bodies reniform, 0.6–0.9 times as long as wide, (2.6–)3.2–
5 mm wide, the ventral surface finely granular-papillose (at 30–40�
magnification) __________________________________________ C. reniformis
46. Perigynia bodies more or less orbicular or rarely obovate, 0.9–1.6
times as long as wide, 1.5–6.1 mm wide, if slightly reniform then
less than 2.6 mm wide, the ventral surface smooth (at 30–40�).
47. Perigynia obovate _______________________________________ C. brevior
47. Perigynia more or less orbicular.
48. Larger perigynia 4–6 mm wide ______________________ C. tetrastachya
48. Larger perigynia 1.5–3.4 mm wide.
49. Larger achenes 1.4–1.8 mm wide, 1.7–2 mm long; larger
perigynia 3.4–4.5 mm long, 2.5–3.3(–3.4) mm wide ______ C. brevior
49. Larger achenes (1–)1.1–1.35 mm wide, 1.3–1.7 mm long;
larger perigynia 2.5–3.9(–4.2) mm long,1.5–2.5 mm
wide ________________________________________ C. festucacea
1. Achenes 3-sided, trigonous or obscurely terete in transverse-section; stigmas 3.
50. Style continuous with the achene, and of the same color and texture as the achene,
persisting.
51. Spike solitary and terminating the flowering culm.
52. Spike androgynous or solely pistillate, 5–18 mm long � 2–3 mm thick; leaf blades
0.5–1.3 mm wide ___________________________________________ C. leptalea subsp. harperi
52. Spike gynecandrous, 30–40 mm long � 12–15 mm thick; leaf blades 3.5–10 mm
wide __________________________________________________________________ C. typhina
51. Spikes two or more per flowering culm, terminal, lateral, or terminal and lateral.
53. Larger perigynia 1 cm long or longer, including beaks.
54. Perigynia with body lanceolate, 2.5 mm wide or less; style straight __________ C. lonchocarpa
54. Perigynia with body narrowly or broadly ovoid, (2.5–)3.5–7 mm wide; style bent
and usually contorted.
55. Pistillate spike outline tending to be globose; perigynia loosely arranged,
spreading, drying dark olive-drab green ___________________________ C. intumescens
55. Pistillate spike outline oblong to cylindric; perigynia either loosely arranged
or not, drying stramineous, green or light olive-drab green.
56. Peduncles of staminate spikes greatly exceeding the uppermost pistillate
spike; perigynia loosely arranged, ascending-spreading __________ C. louisianica
56. Peduncles of staminate spikes shorter than to only slightly exceeding
the uppermost pistillate spike; perigynia either loosely arranged or tightly
arranged.
57. Achenes distinctly wider than long, widest above the middle,
subtruncate to truncate apically; perigynia loose to tightly arranged,
usually squarrose at maturity (± 90° to the rachis) _________________ C. gigantea
57. Achenes as wide as long or longer, widest near the middle, not
subtruncate or truncate apically, perigynia tightly arranged, ascending
or slightly spreading but usually not squarrose.
58. Achene shoulders (area from widest part of the achene to apex)
convex or plane, the angles of achene smooth curved, not
knobbed, the faces flat to slightly concave ___________________ C. lupulina