Jepson eFlora
Key to families | Table of families and genera

Key to Stipa

View taxon page for Stipa

1. Florets 2–6 per spikelet ..... S. mauritanica

1' Florets 1 per spikelet

2. Palea grooved lengthwise

3. Blade 0.8–1.5 mm wide; awns 10–16 mm ..... S. purpurata

3' Blade 0.2–0.4 mm wide; awns 15–25 mm ..... S. chaetophora

2' Palea flat

4. Leaf tips sharp, stiff; lemma awn glabrous to scabrous; fruit ribbed ..... S. brachychaeta

4' Leaf tips acute to acuminate, not both sharp and stiff; lemma awn glabrous to scabrous or hairy; fruit not ribbed

5. Lemma margins in age strongly overlapping entire length, lemma body generally bumpy throughout, tip with crown; palea 1/4–1/2 lemma, glabrous, veins 0

6. Lemma crown generally sharply constricted proximally, distinct from rest of lemma, ± 1/5 lemma, lemma body in age distally ± glabrous ..... S. manicata

6' Lemma crown gradually expanded proximally, weakly to ± distinct from lemma, < 1/6 lemma, lemma body in age distally hairy to ± glabrous, or if crown constricted proximally then lemma body hairy in age

7. Lemma crown hairs 0.3–0.6 mm, awn 12–55 mm, ± 0.1 mm diam, callus 0.4–1.6 mm, lemma body generally hairy in age; stem 0.8–1.2 mm diam ..... S. lepida

7' Lemma crown hairs 0.8–1.1 mm, awn 38–110 mm, 0.2–0.4 mm diam, callus 1.4–3.6 mm, lemma body hairy to mostly glabrous in distal 3/4 in age; stem 1–3.1 mm diam

8. Lemma body in age glabrous in distal 3/4 except on veins ..... S. cernua

8' Lemma body in age hairy throughout ..... S. pulchra

5' Lemma margins in age generally not or only ± overlapping at least part of length, or strongly overlapping in some species with smooth lemmas; lemma bodies generally smooth proximally, tip generally 1–2-lobed; palea 1/3 to ± > lemma, 2-veined at least proximally, generally hairy, or both lemma and palea glabrous

9. Floret callus 1.7–6 mm, sharp-pointed; awn 35–225 mm; perennial herb or annual

10. Lemma awn densely long-hairy and feather-like proximally; perennial herb ..... S. speciosa (2)

10' Lemma awn proximally scabrous to densely hairy but neither long-hairy nor feather-like; perennial herb or annual

11. Annual, florets 4–7 mm; callus 1.7–2.3 mm; awns proximally hairy, hairs generally visible without a hand lens ..... S. capensis

11' Perennial herb; florets 7–13 mm; callus 2–4 mm; awn proximally hairy but hairs generally not easily visible without a hand lens ..... S. comata

12. Distal awn segment 40–120 mm, wavy to curled in age; proximal stem nodes generally concealed by leaf sheaths; panicles in age generally partially enclosed in most distal sheath ..... var. comata

12' Distal awn segment 30–80 mm, straight; proximal stem nodes generally exposed; panicles in age generally fully exserted ..... var. intermedia

9' Floret callus 0.1–2 mm, blunt- to sharp-pointed, awn 3–80 mm; perennial herb

13. Florets <= 2.5 mm; lemma glabrous, occasionally sparsely hairy in Stipa divaricata

14. Leaf blade 0.5–2.5 mm wide, margins generally inrolled; panicle 5–20 cm, proximal inflorescence nodes 1–3-branched ..... S. divaricata

14' Leaf blade 2–10 mm wide, flat; panicle 10–40 cm, proximal inflorescence nodes generally 3–7 branched ..... S. miliacea var. miliacea

13' Florets >= 2.8 mm; lemma hairy throughout or at least in proximal 3/4

15. Florets ± obovoid, length generally <= 3 × width; lemma densely long-hairy at least in youth, awn early-deciduous ..... S. hymenoides

15' Florets elongate-ellipsoid to fusiform, length >= 4 × width; lemma hairy to densely hairy (partly glabrous), awn persistent or not, or if length < 4 × width then awn persistent and floret not densely long-hairy

16. Awns persistent, proximally densely long-hairy, at least some hairs 0.5–8 mm

17. Distal leaves on stem with ligules 3–8 mm; lemma tip 1-lobed, lobe <= 0.1 mm, thick, leathery ..... S. thurberiana

17' Distal leaves on stem with ligules 0.3–3 mm; lemma tip generally 2-lobed or lobes occasionally 0, lobes <= 1 mm, thin, membranous

18. Lemma awn bent 1 ×, proximally densely long-hairy, feather-like, hairs 3–8 mm ..... S. speciosa (2)

18' Lemma awn bent 2 ×, proximally hairy, ± feather-like or not, hairs <= 2 mm

19. Awns proximally with hairs gradually, evenly decreasing in length distally, or hairs of equal length; hairs at lemma tip < or generally ± = longest proximal awn hairs

20. Floret 8–9 mm; lemma 1.2–1.7 × palea; glumes 1.3–1.9 mm wide from midvein to margin ..... S. latiglumis (2)

20' Floret 5.5–7.5 mm; lemma 1.7–2.5 × palea; glumes < 1 mm wide from midvein to margin ..... S. occidentalis (2)

21. Distal awn segment generally densely hairy; stem 0.3–1 mm diam, internodes glabrous; glumes generally ± purple ..... var. occidentalis (2)

21' Distal awn segment generally scabrous or glabrous, occasionally densely hairy at segment base; stem 0.5–2 mm diam, internodes glabrous to densely hairy; glumes generally green

22. Proximal 2 awn segments scabrous or densely hairy, hairs of mixed lengths; lemma tip hairs > proximal awn hairs ..... var. californica (2)

22' Proximal 2 awn segments densely hairy, hairs gradually and evenly shorter towards 1st bend; lemma tip hairs ± = proximal awn hairs ..... var. pubescens (2)

19' Awn proximally with mixed-length hairs, longer hairs mixed with shorter; hairs at lemma tip longer than most proximal awn hairs

23. Florets 8–9 mm; glumes 1.3–1.9 mm wide from midvein to margin ..... S. latiglumis (2)

23' Florets 5–7.5 mm; glumes 0.6–1 mm wide from midvein to margin

24. Callus 0.5–0.7 mm; lemma 1.3–2 × palea; palea tip hairs generally ± 1 mm ..... S. nevadensis

24' Callus 0.8–1.2 mm; lemma 1.7–2.5 × palea; palea tip hairs generally < 1 mm ..... S. occidentalis (2)

25. Distal awn segment generally densely hairy; stem 0.3–1 mm diam, internodes glabrous; glumes generally ± purple ..... var. occidentalis (2)

25' Distal awn segment generally scabrous or glabrous, occasionally densely hairy at segment base; stem 0.5–2 mm diam, internodes glabrous to densely hairy; glumes generally green

26. Proximal 2 awn segments scabrous or densely hairy, hairs of mixed lengths; lemma tip hairs > proximal awn hairs ..... var. californica (2)

26' Proximal 2 awn segments densely hairy, hairs gradually and evenly shorter towards 1st bend; lemma tip hairs ± = proximal awn hairs ..... var. pubescens (2)

16' Awns persistent or not, proximally scabrous or with hairs < 0.5 mm

27. Glumes ovate to narrowly ovate, 3–6 mm; lemma awn 3.9–14 mm

28. Leaf blade ± 0.3 mm wide, thread-like, wavy or curled; inflorescence branches appressed to main axis or not; glumes 3–4.5 mm; lemma awn 10–14 mm ..... S. kingii

28' Leaf blade 0.6–1.4 mm wide, straight, erect, generally folded; inflorescence branches ± appressed to main axis; glumes 3.5–6 mm; lemma awn 3.9–7 mm ..... S. exigua

27' Glumes narrowly lanceolate to lanceolate, >= 6 mm; lemma awn (4)10–80 mm

29. Lemma evenly hairy, hairs 1.2–6 mm, hairs at lemma middle generally ± = hairs at tip of lemma body

30. Awns early-deciduous ..... S. webberi

30' Awns persistent

31. Sheaths not flat and ribbonlike in age; blade margins generally inrolled, 0.2–0.4 mm thick, 0.5–1 mm wide when flat; awn bent 2 × ..... S. pinetorum

31' Sheaths flat and ribbonlike in age; blade 0.5–1.5 mm thick when margins inrolled, <= 7 mm wide when flat; awn bent 1–2 ×

32. Awn bent 2 ×; stem 3–6 mm diam ..... S. coronata (2)

32' Awn bent 1 ×; stem 0.8–2 mm diam ..... S. parishii var. parishii (2)

29' Lemma glabrous or hairs 0.2–1.5(2) mm at lemma middle, distally glabrous or hairy, hairs at lemma middle generally < hairs at tip of lemma body

33. Lemma tip hairs 2–7 mm, generally >= 1 mm > hairs at lemma middle

34. Awn bent 2 ×; stems 3–6 mm diam ..... S. coronata (2)

34' Awn bent 1 ×; stems 0.8–2 mm diam ..... S. parishii var. parishii (2)

33' Lemma tip hairs <= 2.2 mm or 0, generally < 1 mm > hairs at lemma middle

35. Distal awn segment ± wavy ..... S. arida

35' Distal awn segment straight or ± arched

36. Lemma tip 2-lobed, lobes 1–3 mm; palea >= lemma, tip 2-lobed, veins extending into lobes ..... S. stillmanii

36' Lemma tip not lobed or lobes <= 1.2 mm; palea <= lemma, tip unlobed, palea veins ending before or at palea tip

37. Lemma tip lobes thick, stiff, ± 0.1 mm; florets ± compressed ..... S. lemmonii

38. Proximal leaf sheaths, stem glabrous to hairy, not tomentose, hairs <= 0.2 mm ..... var. lemmonii

38' Proximal leaf sheaths, stem tomentose, hairs 0.4–0.6 mm ..... var. pubescens

37' Lemma tip lobes membranous, 0.1–1.2 mm; florets not compressed

39. Proximal internodes densely hairy 3–9 mm below nodes, elsewhere less densely hairy and hairs shorter ..... S. diegoensis

39' Proximal internodes glabrous or ± hairy <= 5 mm below nodes, elsewhere generally glabrous

40. Lemma (1.1)1.2–1.3 × palea; palea tip hairs extending beyond tip; lemma awn 12–25 mm; leaf blades 0.5–2 mm wide ..... S. lettermanii

40' Lemma 1.5–3 × palea; palea tip hairs generally not extending beyond tip; lemma awn 19–31 mm; leaf blades (0.5)1.2–5 mm wide ..... S. nelsonii var. dorei

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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