Directory       News       Site Map       Home
         
    Jepson eFlora
Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

STIPA NEEDLE GRASS

J. Travis Columbus, James P. Smith, Jr. & Douglas H. Goldman


Generally perennial herb, tufted or occasionally rhizomatous. Stem: generally erect, generally unbranched at distal nodes, persistent or not. Leaf: basal or cauline, sheaths open, auricles 0, ligules scarious to membranous, generally ciliate, blade flat to inrolled. Inflorescence: generally panicle-like, generally narrow. Spikelet: generally 1-flowered; glumes generally > floret except awn, membranous, flexible, veins 1–10, awns 0; floret 1(6), generally round (compressed) in ×-section; axis breaking between glumes and floret; callus blunt to sharp, glabrous to hairy; lemma membranous to leathery or hardened, glabrous to hairy, obscurely 3–7-veined, margins overlapping or not, tip entire to 2-lobed or forked, occasionally fused into a crown, 1-awned at or near tip (mucronate), awn (0)3–225(300) mm, unbranched, straight to bent or curled, twisted or not, persistent or not; palea < to > lemma, generally flat, glabrous to hairy, veins (0)2(3). Fruit: ovoid to fusiform, beak 0.
± 600 species: temperate, tropics, generally ± arid, ± worldwide; many species valuable cattle forage, cordage, some weedy. (Greek: stupe or stuppeion, for fiber or cordage, referring to plumose awns of Eurasian species or fibers from especially Stipa tenacissima L.) [Barkworth 2007 FNANM 24:109–186; Columbus & Smith 2010 Aliso 28:65–67] Floret, lemma lengths and shapes in key and text exclude awn. Many related and some poorly defined genera placed here in a broadly treated genus. Hybrids not rare. 4 waifs in California, Stipa caudata Trin. [Amelichloa caudata (Trin.) Arriaga & Barkworth], Stipa clandestina Hack. [Amelichloa clandestina (Hack.) Arriaga & Barkworth], Stipa plumosa Trin. [Jarava plumosa (Spreng.) S.W.L. Jacobs & J. Everett], Stipa tenuissima Trin. [Nassella tenuissima (Trin.) Barkworth] <WEEDINESS SYMBOL 1>. Stipa viridula Trin. [Nassella viridula (Trin.) Barkworth], possibly in California but records unclear.

Key to 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; per

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

Contact/Feedback

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].
We encourage links to these pages, but the content may not be downloaded for reposting, repackaging, redistributing, or sale in any form, without written permission from The Jepson Herbarium.