| # Festuca of North America |

S.G. Aiken, M.J. Dallwitz, C.L. McJannet, and L.L. Consaul

### Festuca rubra subsp. densiuscula Hack. ex Piper

Contrib. U.S. Natl. Herb. 10: 22. 1906. F. densiuscula (Hack. ex Piper) E. B. Alexeev, Byull. Mosk. O-va Ispyt. Prir. Otd. Biol. 87: 113. 1982. F. rubra var. genuina subvar. densiuscula (Hack. ex Piper) St.-Yves, Candollea 2: 240. 1925. Type: U.S.A. California: Crescent City, May-August 1899, Davy 5931. Holotype: US! Isotype: GH!

F. rubra var. littoralis Vasey ex Beal, Grasses N. Am. 2: 607. 1896, non G. Meyer, Chloris Hanover 621, 622. 1836. Type: U.S.A. Oregon: Tillamook Bay, on sand dunes by the sea, July 1882, Thomas Howell s.n. Holotype US! nom. illeg.

F. rubra subsp. arenicola E. B. Alexeev, Byull. Mosk. O-va Ispyt. Prir. Otd. Biol. 87: 115. 1982. Holotype: U.S.A. California: Northern Coast region, sand dunes of ocean at Humbolt Bay, 4 July 1900, J.P. Tracy 894. Holotype: LE. Paratypes also cited by Alexeev (1982): U.S.A. California: Eureka, low moist ground, back of Humbolt Bay, 13 July, 1915, A.S. Hitchcock, Am. Grass Nat. Herb. 469, LE, BR. U.S.A. California: San Francisco, 12 May 1882, M. E. Jones 3251, BR.

The use of the name F. rubra subsp. densiuscula is discussed in Aiken and Fedak (1992).

Habit. Plants yellowish green or bluish gray green (illustrated in the image library), 15–60 cm high, densely tufted or not densely tufted, tiller bases not stiffly erect, bases purplish (sometimes very red), horizontal rooting stems present or absent. Vegetative shoots arising outside, or breaking through the base of existing sheaths.

Vegetative morphology. Sheaths glabrous or glabrescent, not conspicuous at the base of the plant, splitting between the veins, closed more than half their length (most sheaths split early and the margins overlap). Collars glabrous. Auricles absent. Ligules 0.2–0.4 mm long, ciliate. Leaf blades 7–25 cm long, erect, stiffish (stiffer than the leaves of cultivars of F. rubra: usually with more sclerenchyma, but this is variable). Adaxial blade surfaces with trichomes, abaxial blade surfaces glabrous. Leaf blades plicate; 0.5–0.75–1.05 mm wide, 0.65–1.05–1.25 mm deep. Veins 5–7. Adaxial to abaxial sclerenchyma strands absent. Abaxial sclerenchyma well developed, in discrete, relatively narrow strands opposite the veins (the discrete strands maybe relatively large). Ribs 5 (well defined). Uppermost culm leaf sheaths not inflated. Flag leaf blades 0.4–11 cm long. Culm nodes becoming exposed (usually, but not exposed on the type specimen of densiuscula); internodes glabrous.

Floral morphology. Inflorescence 3–9 cm long. Inflorescence branches at the lowest node 1–3, appressed after anthesis, 1.5–4.5 cm long. Rachis angular in cross section, glabrous or sparsely scaberulous. Spikelets aggregated towards the ends of the branches; 3–15 on the longest branches; 7.6–12 mm long, 1.5–3.5 mm wide. Proliferating spikelets absent (not recorded for this taxon). Florets 5–8. Glumes unequal, glabrous (often glaucous), margins ciliate. First glume 2.9–3.7 mm long, veins 1. Second glume shorter than the first lemma, 4.5–5.2 mm long, veins 3. Rachilla internodes antrorsely scabrous. Lemma callus not elongated. Lemma 4.5–7.1 mm long, nerveless in dorsal view or sometimes with only the centre vein distinct, glabrous; apex entire. Lemma awn 0.3–1 mm long (reported to be absent in coastal forms, but usually to 0.3 mm long at least). Palea 5–7 mm long, distinctly pubescent between the keels. Lodicules with marginal teeth, glabrous, 0.7–1.1 mm long. Anthers 2.8–3.8 mm long. Ovary apex glabrous. Caryopsis 3.5–4.5 mm long.

Cytology. 2n = 42.

Habitat and distribution. Native. West coast endemic plants found growing as a sand binders in northern California and Oregon. Northwestern USA: Oreg.; Southwestern USA: Calif.

Classification. Subg. Festuca L.

Notes. On the holotype specimen of this taxon is a folded letter from E. Hackel to C.V. Piper dated 6 Jan. 1903. It reads as follows, with (?) indicating handwritten words that could not be interpreted.

"Dear Sir,

Your letter of Dec. 18, 1902 was followed yesterday by the parcel containing two specimens of F. rubra from California. The specimen gathered at Fort Bragg (Davy 6107) is quite identical with Festuca rubra subvar. pruinosa Hack. in Report of the Bot. Exchange Club of the British Isles for the year 1884, p. 119 (folia pruinose, panicula anjusta, zisculo (?) (?) glabree, (?) pubescentes). This was collected first in the isle of Sky by Linton (?), afterwards I received it from other British coast localities (??? geography) and from the coast of N. France (Bretagne, lg. Crie (?)). The other specimen, from Crescent City (Davy & Blasdale 5931) though very similar to the first has not the stratum of wax on the leaves, which makes one of the characters of subvar. pruinosa, giving them the pruninous aspect. The leaves of the Crescent City plant seem also somewhat glaucous, but only in consequence of the (?) epidermis. It therefore cannot be identified with subvar. pruinosa, but must get a new subvarietal name. Now I find that there is little difference between your specimen Davy + Blasdale 5931 and Howell's Pacif. Coast Pl. (? 1882 no. 74 (76?) (labelled F. ovina v. rubra Gray) and some others of Pringles gathered 1882 on the Coast of California, Mendocino County, which I named in letters to Prof. Scribner: F. rubra var. densiuscula, but without publishing this name. Pringle specimen (I noted no number, only the year 1882, of which I have not example in my herbarium, but which I sent back to Prof. Scribner) must have been (after the notes I took from it) quite the same as yours (5931). Howell's is somewhat different by the awned fertile glumes, less stiff leaves. You may use for your 5931 the name densiuscula or densiflora as you like.

It is evident that there is much variety in the forms of rubra, especially in the coast forms of it and it may perhaps be superfluous to keep all of them with special names. In the sense of my Monographie Festucarum your two specimens might also be united under rubra juncea, but in this case the character of that must be enlarged to enclose also the forms with tight panicles.

I shall always be ready to give you any information on grasses you desire and I shall also make use of your offer to exchange rare species of N. Am. Grasses with those of S. America etc. Mr. Hitchcock will tell you, that I spoke with him (when he called on me here) regarding a large collection of Grasses that I might sell to the Nat. Herbarium. I had not yet the time to go over the whole collection and to complete it (?) types from my herbarium but I shall do so in the lapse of the next month (or 2 months) and then I shall make an offer containing all the number of species and specimens.

Yours ever truly,

E. Hackel."

Aiken and Fedak (1992) reported a chromosome count of 2n=42 obtained for a plant from California, Humbolt County, Fort Bragg, beside the estuary of the Albion River at a Biological Field Station. The plant was one of several growing 2–4 m from the tide line, 12 August 1988, (S.G. Aiken, 88–438. CAN 534351 and 534318). The evidence from the SDS-PAGE analyses of seed proteins (Aiken et al. 1992), suggested that this taxon is closely related to commercial cultivars of F. rubra s.l. and better treated as a subspecies.

In the sand dunes of northern California and southern Oregon there is an apparently native member of the F. rubra s.l. complex that is adapted to saline, sand dune habitats. It differs from commercial F. rubra cultivars in having distinctive glaucous blue foliage that is firm to the touch from underlying well-developed sclerenchyma strands. Another conspicuous difference distinguishing it from commercial F. rubra is that the spikelets have almost awnless lemmas. When grown in the greenhouse, plants developed vivid red leaf sheaths. When plants grow in the unstable moving substrate of seashores and dunes and also when they are grown under greenhouse conditions, they develop vigorous stolons up to 30 cm long. In situations where they were growing between a rock and a well-trodden path, or between rocks, plants were observed to be almost caespitose (S.G. Aiken 88–436, contrasted with 88–437). While the vigour of the stolon development suggests a strong creeping red fescue, the diameter of the stolon is characteristic of a slender creeping red fescue cultivar (D. Huff, Crop Science Dept., Rutgers University, personal communication 1991). At the Biological Field Station at the estuary of the Albon River, commercial F. rubra had been planted for turf. However, around the borders of the lawn it had been undisturbed and in August 1988 was observed to be flowering. No evidence of hybridization was observed between the planted cultivar and the native member of the complex that appeared to have flowered much earlier in the season, even where the plants grew within 3 m of each other.

Alexeev (1982) recognized F. densiuscula (Hack. ex Piper) E. B. Alexeev and also F. rubra subsp. arenicola E. B. Alexeev as a second Californian littoral member of the F. rubra complex. The two taxa were said to differ in the degree of openness of the panicle, the degree of scabrousness of the panicle branches, lemma lengths, and the glaucousness of the leaves. After growing plants from near the type locality of F. rubra subsp. arenicola in the greenhouse for 3 years, examining the collections of coastal F. rubra from the herbaria at CAS and UC, and making some observations of plants growing along the Californian coast, Aiken suggests that there is only one native littoral taxon in northern California. The morphological variation recorded appears to be related to habitat, varying with the degree of exposure to the prevailing wind, how much the sand dunes are moving, and whether the plants grow on or near rocks. The amount of leaf sclerenchyma and the degree of leaf folding appear to vary with the salinity and dryness of the habitat, but even in greenhouse conditions the leaves were observed to remain folded, glaucous, and usually had more sclerenchyma developed in the leaf cross sections than is usual for commercial cultivars of F. rubra (Aiken and Fedak 1991).

Illustrations. • Plants growing in California. Plants of F. rubra subsp. densiuscula, growing in Humbolt County, California. Left, plants influenced by salt spray tended to be brownish yellow; right, plants growing in a relatively sheltered site beside the Albion tidal estuary were conspicuously blue green. • Leaf anatomy. Leaf cross section of F. rubra subsp. densiuscula. Leaf blades are 0.5–0.75–1.05 mm wide and 0.65–1.05–1.25 mm deep, with 5–7 veins. Adaxial to abaxial sclerenchyma strands are absent. Abaxial sclerenchyma are well developed, in discrete, relatively narrow strands opposite the veins. The discrete strands maybe relatively large. There are 5 well defined ribs. • Type specimen: US. Type specimen of F. rubra subsp. densiuscula collected in California, Crescent City, Davy and Blasdale 5931, 30 June 1899. US 556145. Folded onto the top of the specimen taxon is a letter from E. Hackel to C.V. Piper dated Jan. 6, 1903. It reads as follows, with (?) indicating handwritten words that could not be interpreted. "Dear Sir, Your letter of Dec., 1902 was followed yesterday by the parcel containing two specimens of F. rubra from California. The specimen gathered at Fort Bragg (Davy 6107 ) is quite identical with Festuca rubra subvar. pruinosa Hack. in Report of the Bot. Exchange Club of the British Isles for the year 1884, p. 119 (folia pruinose, panicula anjusta, zisculo (?) (?) glabree, (?) pubescentes). This was collected first in the isle of Sky by Linton (?), afterwards I received it from other British coast localities (??? geography) and from the coast of N. France (Bretagne, lg. Crie (?)). The other specimen, from Crescent City ( Davy & Blasdale 5931) though very similar to the first has not the stratum of wax on the leaves, which makes one of the characters of subvar. prunosa, giving them the pruninous aspect. The leaves of the Crescent City plant seem also somewhat glaucous, but only in consequence of the (?) epidermis. It therefore cannot be identified with subvar. pruinosa, but must get a new subvarietal name. Now I find that there is little difference between your specimen Davy + Blasdale 5931 and Howell's Pacif. Coast Pl. (? 1882 no. 74 (76?) (labeled F. ovina v. rubra Gray) and some others of Pringles gathered 1882 on the Coast of California, Mendocino County, which I named in letters to Prof. Scribner: F. rubra var. densiuscula, but without publishing this name. Pringles specimen (I noted no number, only the year 1882, of which I have not example in my herbarium, but which I sent back to Prof. Scribner) must have been (after the notes I took from it) quite the same as yours (5931). Howell's is somewhat different by the awned fertile glumes, less stiff leaves. You may use for your 5931 the name densiuscula or densiflora as you like. It is evident that there is much variety in the forms of rubra, especially in the coast forms of it and it may perhaps be superfluous to keep all of them with special names. In the sense of my Monographie Festucarum your two specimens might also be united under rubra juncea, but in this case the character of that must be enlarged to enclose also the forms with tight panicles. I shall always be ready to give you any information on grasses you desire and I shall also make use of your offer to exchange rare species of N. Am. Grasses with those of S. America etc. Mr. Hitchcock will tell you, that I spoke with him (when he called on me here) regarding a large collection of Grasses that I might sell to the Nat. Herbarium. I had not yet the time to go over the whole collection and to complete it (?) types from my herbarium but I shall do so in the lapse of the next month (or 2 months) and then I shall make an offer containing all the number of species and specimens. Yours ever truly, E. Hackel.". • Isotype specimen: GH. Type specimen of F. rubra subsp. densiuscula collected in Crescent City, May-Aug. 1899, J. Burth Davy 5931. GH Isotype. • Specimen of type in synonymy: US. Specimen of type in synonymy as F. rubra littoralis Vasey. Labels read, "Part of Type ex. Herb Beal C.V.P (Piper). Howell's Pacific Coast Plants. Oregon. F. rubra littoralis Vasey. On sand dunes by the sea Tillamook Bay. July 1882, Thomas Howell." Annotated by Leon E. Pavlick, British Columbia Provincial Museum Nov. 1981, as Cotype F. rubra L. var. littoralis Vasey ex Beal and by P. Auquier, as F. rubra L. subvar. pruinosa Hack. = F. rubra L. subsp. pruinosa (Hack.) Piper, US 556144. • Specimen of type in synonymy: GH. Specimen of type in synonymy as F. rubra var. pruinosa (Hackel) Piper. Collected in California: Mendocino Co., Fort Bragg, July 29, 1899, Davy and Blasdale 6117. GH.

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations with detailed captions, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa. See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Aiken, S.G., Dallwitz, M.J., McJannet, C.L. and Consaul, L.L. 1996 onwards. Festuca of North America: descriptions, illustrations, identification, and information retrieval. Version: 14th February 2019. delta-intkey.com’. Aiken, Dallwitz, McJannet, and Consaul (1997) should also be cited (see References).

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