Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Sagittaria

Sagittaria subulata

arrowhead, sagittaire

awl-leaf arrowhead
Habit Plants perennial, rarely annual, submersed, floating-leaved, or emersed, glabrous to sparsely pubescent; rhizomes often present, occasionally terminated by tubers; stolons often present; corms absent; tubers white to brown, smooth. Herbs, perennial, to 40 cm, on tidal muds; rhizomes absent; stolons present; corms present.
Roots

septate.

Leaves

sessile or petiolate;

petiole terete to triangular;

blade with translucent markings absent, linear to obovate, base attenuate to hastate or sagittate, margins entire, apex round to acute.

submersed, phyllodial, lenticular, 5–40 ´ 0.1–0.4 cm, or rarely floating;

petiole terete, 2.4–4 cm;

blade linear-lanceolate to ovate, 1–2.5 ´ 0.3–1.5 cm.
Inflorescences

racemes, panicles, rarely umbels, of 1–17 whorls, erect, emersed or floating, rarely submersed;

bracts coarse or delicate, apex obtuse to acute, smooth or papillose proximally to distally.

racemes, of 2–7 whorls, floating, 2–11 ´ 1.5–4.5 cm;

peduncles 5–40 cm;

bracts connate more than ¼ total length, subulate, 1.5–4.2 mm, delicate, not papillose; fruiting pedicels recurved, cylindric to club-shaped, 0.2–1.1 cm.
Flowers

unisexual, the proximal rarely with ring of sterile stamens;

staminate flowers pedicellate, distal to pistillate flowers;

pistillate flowers mostly pedicellate, rarely sessile;

bracts subtending pedicels, lanceolate, shorter than pedicels, apex obtuse to acute;

pedicels ascending to recurved;

receptacle convex;

sepals recurved in staminate flowers, recurved to erect in pistillate flowers, often sculptured, herbaceous to leathery;

petals white, rarely with pink spot or tinge, entire;

stamens 7–30;

filaments linear to dilated, glabrous to pubescent;

pistils to 1500 or more, spirally arranged, not radiating in starlike pattern, distinct;

ovules 1;

styles terminal.

0.4–1.2 cm diam.;

sepals spreading to recurved in staminate, erect in pistillate, enclosing flower or fruiting head;

filaments dilated, longer than anther, glabrous;

pistillate pedicellate, occasionally with ring of sterile stamens.
Fruits

without longitudinal ribs, compressed, abaxially keeled or not, abaxial wings often present, lateral wing often present, 1, curved, glands present.

Fruiting

heads 0.55–0.8 cm diam.;

achenes oblanceoloid, abaxially keeled, 2 ´ 1.5 mm, beaked;

faces not tuberculate, wings 1–2, crenate, glands 0–1;

beak lateral, erect, 0.2–0.4 mm.
x

= 11.

2n

= 22.

Sagittaria

Sagittaria subulata
Phenology Flowering summer–fall.
Habitat Streams and brackish bays
Elevation 0–100 m (0–300 ft)
Distribution
from USDA
Mostly Western Hemisphere; Europe; Asia
[BONAP county map]
from FNA
AL; CT; DC; DE; FL; GA; MA; MD; MS; NC; NJ; NY; PA; RI; SC; VA; South America (Colombia)
[WildflowerSearch map]
[BONAP county map]
Discussion

Species ca. 30 (24 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Sagittaria subulata occurs in shallow brackish waters near the coast. The plants are especially common in areas that are exposed during low tides.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Key
1. Fruiting pedicels recurved or rarely spreading; pistillate sepals mostly erect and closely enclosing flower or fruiting head, occasionally spreading to recurved.
→ 2
1. Fruiting pedicels spreading to ascending or absent; pistillate sepals mostly spreading to recurved, not enclosing flower.
→ 9
2. Leaves, at least some, emersed.
→ 3
2. Leaves submersed, floating, rarely emersed, or plants stranded on shore.
→ 5
3. Fruiting heads 1.2–2.1 cm diam.; leaf blade hastate to sagittate
S. montevidensis
3. Fruiting heads 0.7–1.2 cm diam.; leaf blade linear-ovate to lance-elliptic.
→ 4
4. Achenes abaxially keeled, mostly more than 2 mm; faces not tuberculate, often with glands; California.
S. sanfordii
4. Achenes not abaxially keeled, mostly less than 2 mm, faces tuberculate, without glands; e of Rocky Mountains.
S. platyphylla
5. Achene faces tuberculate; floating leaves with sagittate blades present at least on some plants of population.
S. guayanensis
5. Achene faces not tuberculate; floating leaves absent or, if present, with unlobed or hastate blades.
→ 6
6. Fruiting pedicels 0.2–1.1 cm; phyllodia lenticular in cross section; tidal muds; mostly brackish waters.
S. subulata
6. Fruiting pedicels 1.5–6.5 cm; phyllodia flattened in cross section; rarely tidal muds; mostly fresh waters.
→ 7
7. Leaves with blades and petioles usually present on some plants; some plants often stranded along shore, these usually with expanded leaf blades.
S. filiformis
7. Leaves all phyllodia; plants almost always submersed, rarely stranded, these without expanded leaf blades.
→ 8
8. Phyllodia 50–250 cm; Florida springs.
S. kurziana
8. Phyllodia 12–53 cm; streams and lakes, New Mexico.
S. demersa
9. Filaments pubescent to tomentulose (except S. fasciculata).
→ 10
9. Filaments glabrous.
→ 17
10. Leaves all phyllodia, nearly terete; ne United States.
S. teres
10. Leaves with blades and petioles or if phyllodia, then flattened to triangular in cross section; mostly widespread.
→ 11
11. Pistillate flowers sessile to subsessile.
S. rigida
11. Pistillate flowers obviously pedicellate.
→ 12
12. Filaments cylindric.
S. lancifolia
12. Filaments dilated.
→ 13
13. Rhizomes present, coarse; stolons and corms absent.
→ 14
13. Rhizomes absent or if present, then not coarse; corms and/or stolons present.
→ 15
14. Abaxial wing of fruit ± entire; plants widespread
S. graminea
14. Abaxial wing of fruit scalloped or toothed; ne Alabama
S. secundifolia
15. Filaments exceeding anthers in length.
S. cristata
15. Filaments shorter than or equaling anthers in length.
→ 16
16. Blades of emersed leaves 0.5 cm or more wide; w Carolinas.
S. fasciculata
16. Blades of emersed leaves, if present, 0.4(–0.5) cm or less wide; se coastal plain.
S. isoetiformis
17. Emersed leaf blades linear to ovate.
→ 18
17. Emersed leaf blades cordate, sagittate, or hastate.
→ 20
18. Bracts papillose.
S. papillosa
18. Bracts not papillose.
→ 19
19. Emersed plants with erect to ascending petioles; leaf blades lanceolate to ovate.
S. ambigua
19. Emersed plants with recurved petioles; leaf blades linear to sagittate.
S. cuneata
20. Bracts distinct or connate much less than ¼ total length.
→ 21
20. Bracts connate at least ¼ total length.
→ 23
21. Flowers in 2–4 whorls; achenes with facial glands.
S. engelmanniana
21. Flowers in 5–12 whorls; achenes without facial glands.
→ 22
22. Petiole winged in cross section; achene beak strongly recurved.
S. australis
22. Petiole ridged in cross section; achene beak ascending apically.
S. brevirostra
23. Achene beak 1–2 mm, horizontal.
S. latifolia
23. Achene beak 0.1–0.6 mm, erect or incurved.
→ 24
24. Emersed plants with recurved petioles and linear to sagittate blades; basal lobes equal to or shorter than remainder of blade; submersed leaves phyllodial, floating leaves cordate to sagittate
S. cuneata
24. Emersed plants with ascending to erect petioles and sagittate blades; basal lobes longer than remainder of blade; submersed and floating leaves absent.
S. longiloba
Source FNA vol. 22. FNA vol. 22.
Parent taxa Alismataceae Alismataceae > Sagittaria
Sibling taxa
S. ambigua, S. australis, S. brevirostra, S. cristata, S. cuneata, S. demersa, S. engelmanniana, S. fasciculata, S. filiformis, S. graminea, S. guayanensis, S. isoetiformis, S. kurziana, S. lancifolia, S. latifolia, S. longiloba, S. montevidensis, S. papillosa, S. platyphylla, S. rigida, S. sanfordii, S. secundifolia, S. teres
Subordinate taxa
S. ambigua, S. australis, S. brevirostra, S. cristata, S. cuneata, S. demersa, S. engelmanniana, S. fasciculata, S. filiformis, S. graminea, S. guayanensis, S. isoetiformis, S. kurziana, S. lancifolia, S. latifolia, S. longiloba, S. montevidensis, S. papillosa, S. platyphylla, S. rigida, S. sanfordii, S. secundifolia, S. subulata, S. teres
Synonyms Lophotocarpus Alisma subulatum, S. lorata, S. subulata var. natans
Name authority Linnaeus: Sp. Pl. 2: 993. 1753; Gen. Pl. ed. 5; 429, (1754) (Linnaeus) Buchenau: Abhandlungen herausgegeben vom naturwissenschaftlichen Vereine zu Bremen 2: 490. (1871)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:
Northwest Wildflowers