Lycopodium

Øllgaard, Benjamin, Boudrie, Michel & Cremers, Georges, 2020, The Lycopodiaceae of Guyana, Suriname, and French Guiana, Phytotaxa 433 (2), pp. 101-134 : 105

2. LYCOPODIUM L., Sp. Pl. 2: 1100. 1753. Type:— Lycopodium clavatum L., Sp. Pl. 2: 1101. 1753.

As defined here, sporophytes of Lycopodium s. str. are terrestrial, anisotomously branched, with elongate, indeterminate, creeping, or scandent, plectostelic main stems (rhizomes), which, in a dorsolateral position, give rise to usually determinate, ascending to erect, or spreading, repeatedly dorsolaterally branched branchlet systems. Roots emerge directly along the underside of main stems, with plectostelic main roots. Branchlet leaves uniform, terminating in a hyaline hair tip or membranous apex. Strobili erect, simple or forked, borne on simple or forked peduncles or rarely sessile. Sporophylls subpeltate with a thin basal decurrent wing, with a basal mucilage-bearing cavity. Sporangia attached to sporophyll base, reniform, each with a short thick stalk, isovalvate, epidermal cells with thin, lignified, sinuate side walls, with numerous small in- and evaginations. Spores reticulate on all faces. Gametophytes subterranean, mycoheterotrophic; n = 34.

The generic description includes only neotropical representatives of the genus, which has probably only two species in South America. The genus occurs on all continents except Australia. There are 15 species worldwide.

Lycopodium clavatum L., Sp. Pl. 1101. 1753.— Lepidotis clavata (L.) P.Beauv., Prod. Aetheogamie 108. 1805. Type:— Herb. Burser XX: 49 (lectotype UPS, designated by Jonsell & Jarvis 1993: 63). Fig. 2 .

Lycopodium aristatum Willd. , in L., Sp. Pl. ed 4, 5: 17. 1810.— L.clavatum L. var. aristatum (Willd.) Spring , Flora 21 (1): 173. 1838.Type:— VENEZUELA. Caracas: Silla de Caracas, Humboldt & Bonpland s.n. (holotype B [B-W 19351 -01 0]; isotype P! [P00669219]).

Lycopodium piliferum Raddi, Pl. Bras. 1: 79, t. 3. 1825.— L. clavatum L. var. raddianum Spring , Flora 21 (1): 172. 1838.— L. clavatum L. var. piliferum (Raddi) Nessel, Arch. Bot. Est. S. Paulo 1: 435. 1927. Type:— BRAZIL. São Paulo: Mandiocca, G. Raddi s.n. (lectotype PI [PI-011055]; isolectotypes BM, FI-3 sheets, K, P! [P01226667], PI [PI-011056 & PI-011057]).

Lycopodium serpens C.Presl, Rel. Haenkeana 1: 81. 1825, non Poiret (1814).— Lycopodium preslii Grev. & Hook., Bot. Misc. 2: 377. 1831.— L. clavatum L. var. preslianum Spring, Mém. Acad. roy. Belg. 15 [Mon. Lyc. 1]: 90. 1842. Type:— ECUADOR. Guayaquil: Guayaquil, Haenke s.n. (holotype PRC).

Lycopodium trichophyllum Desv., Mém. Soc. Linn. Paris 6: 184. 1827., [as trychophyllum].— L. clavatum L. var. desvauxianum Spring , Flora 21 (1): 173. 1838.— L. aristatum Willd. var. desvauxianum Spring , in Martius, Fl. Bras. 1 (2): 114. 1840.— L. trichiatum Bory var. desvauxianum Spring, Mém. Acad. roy. Belg. 15 [Mon. Lyc. 1]: 92. 1842.— L. clavatum L. var. trichophyllum (Desv.) Nessel, Arch. Bot. Est. S. Paulo 1: 436. 1927. Type:— BRAZIL. “Habitat in Brasilia,” collector unknown, in Herb. Desvaux (lectotype P [P00559088], designated by Øllgaard 1988: 125).

Lycopodium eriostachys Fée, Crypt. Vasc. Brésil 1: 224. 1869.— L. clavatum L. var. eriostachys (Fée) Nessel & Hoehne, Arch. Bot. Est. S. Paulo 1: 435. 1927.—Type: BRAZIL. Rio de Janeiro: Brasilia fluminensi, Serra os Orgaos, Glaziou 1788 (lectotype RB!, designated by Øllgaard & Windisch 2014: 300; isolectotypes BR!, C!, P [P00559076] & [P00559083]).

Plants creeping, trailing, or hanging over banks. Main stem usually above ground, rooting with long intervals, 2– 3(–4) mm thick excluding leaves. Aerial shoots ascending to stiffly erect, to at least 50 cm tall, repeatedly unequally branched, with strongly diverging to almost parallel branchlets. Ultimate branchlets terete. Leaves borne in low alternating spirals or whorls of 6–8(–10), forming 12–16(–20) indistinct longitudinal ranks, patent to ascending or imbricate, linear-acicular, 6–8(–10) × 0.5–0.8 mm, terminating in a long hyaline hair or hyaline apex, with smooth to sparsely denticulate margins. Strobili sessile or pedunculate. Peduncles, if present, terminating main branchlets, erect, to 30 cm long, simple, or branched and bearing to 6 pedicellate strobili. Peduncle leaves distant, appressed, reduced in length, partially membranous. Strobili 1.5–6(–8) cm long, ca 6 mm in diam. incl. sporophylls, sometimes forked. Sporophylls borne in alternating whorls of 5–6, forming 10–12 longitudinal ranks, subpeltate, with a median, basiscopic, membranous wing on the stalk, connecting the basiscopic flap of the exterior face to the strobilus axis, with triangular-ovate to rhombic-ovate, acuminate exterior face, with usually broadly scarious, dentate to erose-laciniate margins. Sporangia 1.3–1.6 mm in diam. Spores reticulate on all faces. n = 34.

Distribution: —Almost cosmopolitan, found in humid temperate and boreal regions of the northern hemisphere, and on tropical mountains of the Old and New Worlds; absent from Australia.

Habitat: —Terrestrial and rupestral, trailing or scrambling in open and usually humid places such as road cuts, roadsides, rock crevices, trail margins, often in pioneer habitats.

Specimens examined:— GUYANA. Mazaruni-Potaro: Roraima, summit, La Proa Camp, East of border, near Lake Gladys, Liesner 23291 (MO, NY).

Notes: — Lycopodium clavatum is highly variable and adaptive to external factors. The cited specimen belongs to the type subspecies. Lycopodium clavatum subsp. contiguum (Klotzsch) B.Øllg. (1988:126) does not occur in the Guianas and is retricted to the high Andes and high mountains in Central America. Funk et al. (2007) report this species from Guyana. I have not seen the specimens, but there are several specimens cited from the Cuyuni-Mazaruni area in the US specimen database.

Figures

FIGURE 2. Lycopodium clavatum—(Ecuador, Harling 4091, S) A. Growth habit. A1. Leaf. A2. Sporophyll. Drawing by B. Johnsen.