Luzula sect. Luzula

Zika, Peter F., Wilson, Barbara L. & Kirschner, Jan, 2015, The Luzula comosa complex (Luzula section Luzula, Juncaceae) in western North America, Phytotaxa 192 (4), pp. 201-229 : 225

Key to the species of Luzula sect. Luzula in western North America

The measurements for Luzula multiflora differ in separate leads in the key, because by necessity we are including what we believe are different subspecies or species under the name L. multiflora . The L. multiflora complex in North America requires further research before a stable and accurate classification of its members is established.

1. Plants with horizontal rhizomes, lacking bulbous bases....................................................................................................................2

1- Plants cespitose, bases often bulbous, rarely with short vertical rhizomes........................................................................................5

2. Seeds 0.95–1.6 mm long, including aril 0.15–0.45 mm ....................................................................................................................3

2- Seeds usually 1.6–2.1 mm long, including aril 0.4–0.8 mm ..............................................................................................................4

3. Stem leaves usually <5 mm wide ; seeds (0.95) 1.1–1.6 mm long including aril; tepals pale to dark brown; montane wet meadows and peatlands; southern Washington south to California, east to western Montana .................................................... L. cascadensis

3- Stem leaves> 5 mm wide; seeds 1.2–1.3 mm long including aril; tepals dark brown to blackish; maritime habitats in coastal Alaska and northeastern Asia ...................................................................................................................................................... L. kobayasii

4. Anthers 0.6–0.9 mm ; tepals 2.5–3.1 mm; styles 0.3–0.6 mm; low elevation coastal wet meadows and peatlands; northern Vancouver Island north to Alaska .............................................................................................................................................. L. multiflora

4- Anthers (1) 1.5–2 mm; tepals 2.8–4.2 mm; styles 0.5–1.5 mm; low elevation uplands and disturbed soils ........................................ ......................................................................................................................................................... L. campestris subsp. campestris

5. Tepals pale, whitish to pale brown or medium brown ........................................................................ L. comosa (with 2 varieties) 6

5- Tepals dark brown to blackish ...........................................................................................................................................................7

6. Inflorescences dense, unbranched; range coastal .......................................................................................... L. comosa var. comosa

6- Inflorescences usually umbellate, branched; range coastal and inland ............................................................... L. comosa var. laxa

7. Inflorescences dense, unbranched.....................................................................................................................................................8

7- Inflorescences branched, umbellate................................................................................................................................................13

8. Habitat low to moderate elevation, non-arctic sites, including coastal southern Alaska ................................................................. 9

8- Habitat alpine and arctic sites..........................................................................................................................................................11

9. Stem base not bulbous ; stem leaves usually 5–8 mm wide; seeds up to 1.4 mm long, including aril often 0.2–0.3 mm long; coastal Alaska and northeastern Asia .......................................................................................................................................... L. kobayasii

9- Stem base bulbous ; stem leaves usually <6 mm wide; seeds up to 1.85 mm long, including aril 0.15–0.6 mm long; southwestern British Columbia south to California ............................................................................................................................................. 10

10. Fertile culms usually lacking a long-peduncled axillary spike from a lower node; tepals medium brown; seeds 0.6–0.9 mm wide ................................................................................................................................................ unusually dark L. comosa var. comosa

10- Fertile culms often with a long-peduncled axillary spike from a lower node; tepals dark brown to blackish; seeds 0.7–1.1 mm wide ................................................................................................................................................................................ L. subsessilis

11. Anthers 0.6–1.3 mm; seeds 0.8–1 mm wide, 1.5–1.8 mm long, including aril 0.3–0.5 mm; base bulbous ................... L. multiflora

11- Anthers 0.3–0.6 mm; seeds 0.5–0.7 mm wide, 0.9–1.2 mm long, including aril 0.1–0.25 mm; base not bulbous ....................... 12

12. Leaves 3–4 mm wide ; tepals 2.3–2.9 mm; seed arils 0.1–0.25 mm; Sierra Nevada Range of California and Wallowa Mountains of Oregon ........................................................................................................................................... L. orestera Sharsmith (1958: 125)

12- Leaves 1.4–3 mm wide; tepals 1.9–2.5 mm; seed arils 0.1–0.15 mm; northern British Columbia, Alaska, and east across northern Canada............................................................................................................................... L. groenlandica Böcher (1950: 18 , pl. 1)

13. Plant base not bulbous; flowers and fruits dense, compact, and contiguous at spike bases............................................................14

13- Plant base bulbous; flowers and fruits at base of spikes dense or somewhat scattered or loosely arranged at spike bases............15

14. Stem leaves 4.5–8 mm wide, usually broader than basal leaves; basal leaves 5–6 mm wide; inflorescence bracts often prominent; rays of umbel often with secondary terminal branching; pedunculate clusters often with 2–4 subclusters; coastal southern Alaska, the Aleutian Is., Kamchatka, and the northern Kurile Is ................................................................................................. L. kobayasii

14- Stem leaves usually 1–5 mm wide, usually narrower than basal leaves ; basal leaves 1.8–6 mm wide; inflorescence bracts not prominent; rays of umbel rarely with secondary branching; pedunculate clusters usually simple; widespread, coastal Alaska south to Oregon and east across North America , Eurasia ......................................................................................................... L. multiflora

15. Anthers (1.1)1.2–2.8(3.1) mm; longer tepals usually 3.6–5.8(6.1) mm; styles (0.7) 0.8–2.3 mm; coastal, foothills and lower mountain slopes, southwestern British Columbia south to California ................................................................................... L. macrantha

15- Anthers 0.5–0.9(1.1) mm ; longer tepals 2.2–4.2 mm; styles 0.2–0.9(1.1) mm; coastal lowlands and montane to subalpine meadows, inland to Alberta, South Dakota, and New Mexico ................................................................................................................16

16. Some spikes with slightly loose or scattered distal flowers/fruits; coastal, foothills, and montane .................................................... ....................................................................................................................................... unusually dark forms of L. comosa var. laxa

16- Spikes dense distally; subalpine meadows .................................................................................................................... L. multiflora