Najas guadalupensis
Beitrage zur Kenntniss der Gattung Najas 8. 1870.
Stems often profusely branched distally, 11–90 cm × 0.1–2 mm; internodes 0.1–9 cm, without prickles. Leaves spreading with age, 0.3–3.3 cm, lax in age; sheath 1–3.4 mm wide, apex rounded to truncate; blade 0.2–2.1 mm wide, margins minutely serrulate, teeth 18–100 per side, apex rounded to truncateslightly auriculate, with 1–3 teeth, teeth unicellular; midvein without prickles abaxially. Flowers 1–3 per axil, staminate and pistillate on same plants. Staminate flowers in distal axils, 1.5–3 mm; involucral beaks 4-lobed, 0.2–1.3 mm; anther 1- or 4-loculed, 1–1.7 mm. Pistillate flowers in proximal axils, 1.5–4 mm; styles 0.3–1.5 mm; stigmas 4-lobed. Seeds not recurved, yellowish white with purple tinge, fusiform, 1.2–3.8 × 0.4–0.8 mm, apex with style situated at center; testa dull, 3 cell layers thick, pitted; aeroleareoles regularly arranged in 20–60 longitudinal rows, not ladderlike, 4–6-angled, longer than broad, end walls not raised. 2n = 12, 36, 42, 48, 54, 60.
Distribution
Alta., Man., Ont., Que., Ala., Ariz., Ark., Calif., Colo., Conn., D.C., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Miss., Mo., Mont., N.C., N.H., N.J., N.Y., Nebr., Nev., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Widespread.
Discussion
By having unicellular teeth on the leaf margin, Najas guadalupensis resembles N. flexilis and N. graminea. The seeds of N. guadalupensis are pitted; those of N. flexilis are smooth. The sheaths of N. guadalupensis are rounded to slightly auriculate; those of N. graminea are deeply auriculate.
Subspecies 4 (4 in the flora).
Selected References
None.
Lower Taxa
Key
| 1 | Seeds 3.3–3.8 mm; aeroleareoles of testa arranged in 50–60 longitudinal rows | Najas guadalupensis subsp. muenscheri |
| 1 | Seeds 2.5 mm or less; aeroleareoles of testa in fewer than 50 longitudinal rows. | > 2 |
| 2 | Teeth of leaf blade evident to unaided eye; anthers 1-loculed | Najas guadalupensis subsp. floridana |
| 2 | Teeth of leaf blade invisible to unaided eye; anthers 4-loculed. | > 3 |
| 3 | Leaf blade with 50–100 teeth per side; stems 0.8 mm or less diam. | Najas guadalupensis subsp. guadalupensis |
| 3 | Leaf blade with 20–40 teeth per side; stem 1 mm or more diam. | Najas guadalupensis subsp. olivacea |