Fimbristylis crosslandii Roalson, R.L.Barrett, & Larridon, 2019

Roalson, Eric H., Barrett, Russell L., Wilson, Karen L., Bruhl, Jeremy J. & Larridon, Isabel, 2019, Crosslandia setifolia is a partly monoecious species of Fimbristylis (Abildgaardieae: Cyperaceae), Phytotaxa 399 (2), pp. 163-166 : 163-165

Fimbristylis crosslandii Roalson, R.L.Barrett, & Larridon , nom. nov.

Replaced name: Crosslandia setifolia W.Fitzg. (1906: 9) , non Fimbristylis setifolia Hochst. ex Richard (1850: 507) (= Bulbostylis atrosanguinea ( Boeckeler 1886: 276) Clarke (in Durand & Schinz 1894: 611)).

Type (lectotype here designated): AUSTRALIA. Western Australia: Goody Goody Well, 9 miles from Derby , April 1905, W. V. Fitzgerald 259 (lectotype: PERTH 01030485 !; isolectotypes: BM 000990949 !, image!, BRI 340661 !, image!, NSW 426509 !, PERTH 01030493 !) .

Notes: The name is usually ascribed to Fitzgerald (1918: 122); however, a brief but diagnostic description was published by Fitzgerald (1906: 9). The species is widespread from the Dampier Peninsula in Western Australia ( Kenneally et al. 1996: 204) to the Top End of the Northern Territory. A full description can be found in Rye (1992: 1041; as Crosslandia setifolia ). The epithet is based on the genus Crosslandia , which recognizes Charles Crossland, leader of the expedition on which this species was discovered ( Maslin & Cowan 1998).

We here designate PERTH 01030485 as lectotype as it has the largest number of fertile spikelets and an original specimen label in Fitzgerald’s hand. No specimens were cited by Fitzgerald (1906: 9) other than general reference to his own collections, so the lectotype is chosen from the collection cited by Fitzgerald (1918: 122). Fitzgerald’s primary set of specimens is held at PERTH, but distribution of duplicates was not consistent, so lectotypification is considered desirable, as discussed by Maslin and Cowan (1998).

This species is easy to recognize by its distinctive fertile spikelets held just above ground level in addition to the normal, aerial fertile spikelets ( Fig. 1 ). This species was originally described as being monoecious, but it is now known to be variable and is partly hermaphroditic as is typical of Fimbristylis . The morphology of the nutlets is somewhat dimorphic between the two spikelet types ( Fig. 1 ). While most basal spikelets appear sessile, occasionally the culm can elongate to hold them a few cm above ground level.

Fimbristylis crosslandii appears to be closely related to F. spiralis R.Br. (1810: 226) , which can also develop fertile spikelets at the base of the plant ( Clarke 2005), and is clearly congeneric.

Figures

FIGURE 1. Fimbristylis crosslandii. A–C. Basal spikelets with styles (black arrows). D–F. Aerial spikelets with styles (black arrows) and old stamens (white arrows). G–I. Nutlets (two bottom nutlets in G from basal spikelets, all others from aerial spikelets). Images: A–F from R.L.Barrett, M.D.Barrett & B.M.Anderson RLB 8019 (PERTH), images by Russell Barrett; G from M.Gray 5703 (CANB); H, I from J.Bruhl 368 (CANB), images by Jessie Knott. Scale bar = 0.5 mm.