LOC. "It takes the place of the gum-tree (Eucalyptus) in the creeks about lat. 29 degrees 30 minutes S." D. Sturt.
OBS. It is difficult to distinguish this species, which, according to Captain Sturt, forms a tree about 20 feet in height, from Grevillea striata. I have endeavoured to do so in the above specific difference, contrasted with which the leaves of G. striata have always more than 10 striae, which are hardly twice the breadth of the pubescent interstices, and the cicatrices of whose leaves are longer than broad, and more or less acute, both above and below. This is a source of character which in the supplement to the Prodr. Florae Novae Hollandiae, I have employed in a few cases both in Grevillea and Hakea, but which I believe to be important, as it not only expresses a difference of form, but also in general of vascular arrangement.
25. PTILOTUS (latifolius) capitulis globosis, bracteis propriis calycem superantibus, foliis ovatis petiolatis.
LOC. "In lat. 26 degrees S."--D. Sturt.
DESC. Herba diffusa, ramosa, incana. Folia alterna, petiolata, lateovata, integerrima. Capitula ramos terminantia, solitaria vel duo approximata. Bracteae laterales scariosae, sessiles, late ovatae, enerviae. Perianthium; foliolis subaequalibus, lana implexa alba basi tectis, ante expansionem ungue nervoso tunc brevissimo, post anthesin laminam scariosam enervem fere aequante. Stamina 5 antherifera; filamenta basi in cyathulum edentulum connata. Antherae biloculares, loculis utrinque distinctis medio solum conjunctis. Ovarium monospermum, glabrum. Stylus filiformis, glaber. Stigma capitatum, parvum. Utriculus evalvis, ruptilis.
OBS. I was at first inclined to consider this plant as a genus distinct from Ptilotus, more, however, from the remarkable difference in habit than from any important distinction in the flower, for its character would have chiefly consisted in the great size of its lateral bracheae, and in the form of its antherae.
In a small collection formed during the voyage of Captains Wickham and Stokes, there is a plant very nearly related to, and perhaps not specifically distinct from Ptilotus latifolius, but having narrower leaves. It was found on one of the islands of Dampier's Archipelago.
26. NEURACHNE (paradoxa) glaberrima, culmo dichotomo, foliis rameis abbreviatis, fasciculis paucifloris, glumis perianthiisque imberbibus valvula exteriore cujusve floris septemnervia.
LOC. Nulla indicatio loci v. stationis, in Herbario. D. Sturt.
DESC. Gramen junceum, facie potius Cyperaceae cujusdam. Folia radicalia in specimine unico viso defuere; ramos subtendentia abbreviata, vagina aperta ipsum folium superante; floralia subspathiformia sed foliacea nec membranacea. Fasciculi pauciflori: spiculae cum pedunculo brevissimo articulatae et solubiles, et subtensae bractea nervosa carinata ejusdem circiter longitudinis. Gluma bivalvis biflora, nervosa, acuta, mutica; valvulae subaequales septemnerviae; exterioris nervis tribus axin occupantibus sed distinctis reliquis per paria a marginibus et axilibus subaequidistantibus; interioris nervis aequidistantibus, externis margine approximatis. Perianthium inferius (exterius), bivalvis, neuter; valvula exterior septemnervis, exteriori glumae similis textura forma et longitudine; valvula interior (superior) angustior pauloque brevior, dinervis, nervis alatis marginibus veris latis induplicatis. Perianthium superius hermaphroditum, paulo brevius, pergamineo-membranaceum, nervis dilute viridibus; valvula exterior quinquenervis, acuta, concava; interior ejusdem fere longitudinis, dinervis. Stamina 3, filamentis linearibus. Ovarium oblongum, imberbe. Styli duo. Stigmata plumosa, pallida?