Hooveria (plant)

Chromosome number is 2n = 60

In 1940, Robert F. Hoover, on his monograph of Chlorogalum, noted a division in the genus on the basis of diurnal and vespertine flowering species. He also noted that the same two diurnal species had similar floral morphology. He kept the genus whole on the basis that their vegetative morphology and geographic distribution was quite close and consistent.^[4][1]

In 1970, a study reported that the vespertine species have chromosome numbers ranging from 2n = 30 to 2n = 36, while the two diurnal species have a chromosome number of 2n = 60. The karyotypes of the diurnal species were noted to have five, instead of six pairs of large chromosomes, which means they were not simply just polyploids formed from the doubling of a 2n = 30 base.^[5][1]

In 2013, a study of the phylogenetics in the Chlorogaloideae subfamily also suggested that the genus Chlorogalum was not monophyletic. Their analysis showed that the vespertine species form a well-supported clade that excluded the diurnal species. The diurnal species were suggested to be sister to a larger clade comprising the vespertine Chlorogalum, Hastingsia, and Camassia.^[6][1]

Another study in 2015 of the Chlorogaloideae subfamily with molecular phylogenetic tools showed that Chlorogalum is not monophyletic, and that the two diurnal species were placed in a clade that is sister to the remainder of the Chlorogaloideae consisting of the vespertine Chlorogalum, along with Hastingsia, and Camassia.^[7][1]

A 2018 paper in Phytoneuron described Hooveria as a taxonomic genus, composed of the two diurnal species, based on the evidence provided by the phylogenetic research that Chlorogalum comprises two lineages.^[1]

• Hooveria parviflora (S.Watson) D.W.Taylor & D.J.Keil
• Hooveria purpurea (Brandegee) D.W.Taylor & D.J.Keil

The genus is disjunct in distribution. The northern species, Hooveria purpurea is native to Monterey and San Luis Obispo counties, where it is found in foothill woodland areas. The second species, Hooveria parviflora, is found in southeastern Los Angeles and southwest Riverside counties, but is primarily distributed in coastal Orange County and San Diego County, crossing over the border into extreme northwestern Baja California, and it grows in open clearings of chaparral, coastal sage scrub, grassland and open woodlands.^[3]