Otholobium lanceolatum

Otholobium lanceolatum is a small subshrub of up to 20 cm (7.9 in) high, with few leaves, that is assigned to the Pea family. Up to seven stems of 9–15 cm (3.5–5.9 in) long grow from a short thickened trunk, spread horizontally at their base but have rising tips. The plants regrow from the underground woody rootstock after fire destroys the above ground biomass. These stems occasionally branch from one of the lower axils. At the base of the leaf are two hairless, awl-shaped, pointy, ribbed, gland bearing stipules of 3–5 mm (0.12–0.20 in) long and 0.5–2 mm (0.020–0.079 in) wide, which is longer than the petioles. In contrast to most Otholobium species, the leaf only consists of one leaflet. The ancestral clover-like leaf can still be deduced from the fact that the petiole of about 2 mm (0.079 in) long is topped by a petiolule of about 1 mm (0.039 in) long that can be shed separately. It in turn carries the single leaflet that can also be shed separately. The first leaves to appear in the season are densely set with warts and smaller than later leaves. The hairless leaflet is elliptic, 2.5–3.6 cm (0.98–1.42 in) long and 0.6–1 cm (0.24–0.39 in) wide, with a wedge-shaped base, the edge set with glands, a pointy end, but the central vein is elongated beyond the leaf blade in a straight tip. The midvein is prominent on the underside of the leaflet while the secondary veins are somewhat raised on both surfaces but less conspicuous.^[2]

The oblong inflorescences emerge individually or in pairs in the axils of the youngest leaves of short, young shoots on 25–35 mm (0.98–1.38 in) long peduncles (about double the length of the subtending leaf) that are densely set with warts of about 0.2 mm (0.0079 in) high. The inflorescences themselves are 35–55 mm (1.4–2.2 in) long, and carry between 5 and 9 clusters of three flowers each that are borne on 2–4 mm (0.079–0.157 in) long pedicels. Each flower cluster is subtended by a fan-shaped to broadly oval-oblong, hairy bract, that carries glands and is eventually shed. The flowers are 8–10 mm (0.31–0.39 in) long, and initially are each subtended by a narrowly lance- to line-shaped bract of about 3 mm (0.12 in) long that is eventually shed. The calyx is merged in a bell-shaped tube of 2–3 mm (0.079–0.118 in) long but ends in five teeth. Its outer surface is covered in spreading, white 1.5–2 mm (0.059–0.079 in) long hairs and many small glands, but hairless on the inside. All teeth have a pointy tip. The tooth at the bottom of the flower is dark green, much longer (10–11 mm (0.39–0.43 in)) and wider (2–2.5 mm (0.079–0.098 in)) than the other four. These other teeth are pale yellowish green in colour. The two teeth adjoining the standard are sickle-shaped and fused together for about a third of their length, and about as long as the teeth to the sides of the flower. As in most Faboideae, the corolla is zygomorph, forms a specialized structure and consists of five free, white petals. The upper petal, called the banner or standard, is white to pale blue, about 13 mm (0.51 in) long and 8–9 mm (0.31–0.35 in), inverted egg-shaped, but oblong when the blade is curved backwards. The blade of the standard is extending down into a narrowed part called claw of about 2 mm (0.079 in) long. The two side petals called wings are shaped like a pruning knife, curving up relative to the keel, 10–12 mm (0.39–0.47 in) long and 3–4 mm (0.12–0.16 in) wide. The blade of the wing is adorned with an area of ridges and has one lobe or auricle facing the base. The claw of the wing is about 3 mm (0.12 in) long. The wing petals envelop and are very lightly attached to the keel. The two keel petals are fused at the bottom and form a boot-like structure. The keel petals are white with a purple blotch at the tip, about 9 mm (0.35 in) long and 2.5–3 mm (0.098–0.118 in) and extend towards the base in a narrowed claw of about 4 mm (0.16 in) long. The keel envelops a hollow, open tube of about 8 mm (0.31 in) long, made up of nine merged filaments and one free stamen. The anthers are all equal and approximately 0.3 mm (0.012 in) long. Largely hidden in this androecium is an approximately 8 mm (0.31 in) long pistil, including at its base a gynophore of about 1 mm (0.039 in) long that carries the softly hairy ovary of 1.8–2 mm (0.071–0.079 in) long. At the tip, the ovary extends into a sparsely hairy, forward sloping style that strongly widens at the place where it curves upwards 2.5–2.8 mm (0.098–0.110 in) from its end. The style is topped by a stigma with few brushlike hairs. Fruits and seeds were unknown at the time of the description of this species.^[2]

Otholobium lanceolatum can be distinguished from O. rotundifolium, which has inverted egg-shaped leaflets of 10–18 mm wide with minute teeth along its edge and the midvein only slightly emerging beyond the tip (not elliptic leaflets of 6–10 mm wide with smooth margins and a conspicuously extended midvein), club-shaped stipules (not awl-shaped), the inflorescences consist of 3–5 pairs or triplets of flowers (not 5–9 triplets), and the calyx teeth are approximately equally long (not very unequal teeth). O. dreweae and O. thomii are clump-forming subshrubs that are densely set with leaves and have distinctly ridged herbaceous stems without dot-like glands, and pale to reddish purple flowers (not open, sparsely leaved woody subshrubs, with branches covered in warts or dots but without ridges, and white flowers with a purple keel tip). O. zeyheri in which the leaves that are higher on the stems have 3 leaflets (not all leaves with just one leaflet), carries spikes that consist of 25-30 sets of 3 flowers, on a stalk that is 4-5 times longer than the subtending leaf (not 5-9 triplets on an inflorescence stalk that is only double the length of the leaf).^[2]