Question: Which genus between Borago and Banksia has the greatest number of species within the genus?
Context: Banksia" ser.  "Tetragonae is a taxonomic series in the genus "Banksia".  It consists of three closely related species of erect shrub with pendulous inflorescences in section "Banksia".  These are "B. lemanniana" (Lemann's Banksia), "B. caleyi" (Cayley's Banksia) and "B. aculeata" (Prickly Banksia). Banksia" sect.  "Banksia is one of four sections of "Banksia" subgenus "Banksia".  It contains those species of subgenus "Banksia" with straight or sometimes curved but not hooked styles.  These species all have cylindrical inflorescences and usually exhibit a bottom-up sequence of flower anthesis.  It is a widely distributed section, with taxa occurring in both the south west and east coastal distributions of the genus. Banksia sessilis, commonly known as parrot bush, is a species of shrub or tree in the plant genus "Banksia" in the family Proteaceae.  It had been known as Dryandra sessilis until 2007, when the genus "Dryandra" was sunk into "Banksia".  The Noongar peoples know the plant as Budjan or Butyak.  Widespread throughout southwest Western Australia, it is found on sandy soils over laterite or limestone, often as an understorey plant in open forest, woodland or shrubland.  Encountered as a shrub or small tree up to 6 m in height, it has prickly dark green leaves and dome-shaped cream-yellow flowerheads.  Flowering from winter through to late spring, it provides a key source of food—both the nectar and the insects it attracts—for honeyeaters in the cooler months, and species diversity is reduced in areas where there is little or no parrot bush occurring.  Several species of honeyeater, some species of native bee, and the European honey bee seek out and consume the nectar, while the long-billed black cockatoo and Australian ringneck eat the seed.  The life cycle of "Banksia sessilis" is adapted to regular bushfires.  Killed by fire and regenerating by seed afterwards, each shrub generally produces many flowerheads and a massive amount of seed.  It can recolonise disturbed areas, and may grow in thickets. Banksia is a genus of around 170 species in the plant family Proteaceae.  These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads.  Banksias range in size from prostrate woody shrubs to trees up to 30 metres tall.  They are found in a wide variety of landscapes; sclerophyll forest, (occasionally) rainforest, shrubland, and some more arid landscapes, though not in Australia's deserts. Banksia serrata, commonly known as old man banksia, saw banksia, saw-tooth banksia and red honeysuckle, is a species of woody shrub or tree of the genus "Banksia" in the family Proteaceae.  Native to the east coast of Australia, it is found from Queensland to Victoria with outlying populations on Tasmania and Flinders Island.  Commonly growing as a gnarled tree up to 16 m (50 ft) in height, it can be much smaller in more exposed areas.  This "Banksia" species has wrinkled grey bark, shiny dark green serrated leaves and large yellow or greyish-yellow flower spikes appearing over summer.  The flower spikes, or inflorescences, turn grey as they age and pollinated flowers develop into large, grey, woody seed pods called follicles. Borago, or borage, is a genus of five species of herbs native to the Mediterranean, with one species, "Borago officinalis" cultivated and naturalized throughout the world. Banksia seminuda, commonly known as the river banksia, is a tree in the plant genus "Banksia".  It is found in south west Western Australia from Dwellingup (32°42′ S) to the Broke Inlet east of Denmark (34°57′ S).  It is often mistaken for, and was originally considered a subspecies of, the "Banksia littoralis" (Swamp Banksia).  Stephen Hopper described the subspecies "remanens" as a short-leaved shrubby form found in the coastal sands below granite outcrops in the Walpole-Nornalup National Park, however George does not feel this form warrants taxonomic recognition as it lies within the normal variability of the species and there was no clear distinction between it and the other populations of "B. seminuda". Banksia" ser.  "Crocinae is a taxonomic series (botany) in the genus "Banksia".  It consists of four closely related species, all of which are endemic to Western Australia; namely "B. prionotes" (Acorn Banksia), "B. burdettii" (Burdett's Banksia), "B. hookeriana" (Hooker's Banksia) and "B. victoriae" (Woolly Orange Banksia).  The series was first published by Alex George in 1981, but discarded by Kevin Thiele and Pauline Ladiges in 1996, and finally reinstated by George in 1999.  Recent cladistic analyses suggest that it is monophyletic or nearly so. Banksia marginata, commonly known as the silver banksia, is a species of tree or woody shrub in the plant genus "Banksia" found throughout much of southeastern Australia.  It ranges from the Eyre Peninsula in South Australia, to north of Armidale, New South Wales, and across Tasmania and the islands of Bass Strait.  It grows in various habitats, including "Eucalyptus" forest, scrub, heathland and moorland.  "Banksia marginata" varies widely in habit, ranging from a small shrub, 20 cm high, to a large tree, 12 m tall.  The narrow leaves are linear and the yellow inflorescences (flower spikes) occur from late summer to early winter.  The flower spikes fade to brown and then grey and develop woody follicles bearing the winged seeds.  Originally described by Antonio José Cavanilles in 1800, further collections of "B. marginata" were described as several separate species by Robert Brown in 1810.  However, all were reclassified as a single species by George Bentham in 1870.  No distinct subspecies have been recognised by "Banksia" expert Alex George, who nonetheless concedes that further work is needed. Banksia plagiocarpa, commonly known as the Dallachy's banksia or blue banksia, is a species of shrub or tree in the plant genus "Banksia".  It occurs only on Hinchinbrook Island, Queensland and the immediately adjacent mainland.  First collected in 1867, "Banksia plagiocarpa" was not described until 1981, when Alex George named it in his monograph of the genus "Banksia".  Genetic studies show it to be related to "Banksia aquilonia", "Banksia oblongifolia" and "Banksia robur".
Answer: Banksia