There may be several subspecies of native morning glories (Calystegia macrostegia) on Owens Peak. They are difficult to separate in taxonomic keys and there appears to be intergradation between some subspecies. I have seen populations in the hills northwest of Palomar College (before they were covered with houses) that resembled ssp. arida, ssp. intermedia and ssp. tenuifolia (see plant list for hills northwest of Palomar College). At this time I am torn between ssp. arida and ssp. tenuifolia for Owens Peak; however, it depends on which flora you are using. By the way, most of our beautiful cultivated morning glories, including the sweet potato, belong to the genus Ipomoea.

In his book, Sea Routes to Polynesia (1968), Thor Heyerdahl postulated that sweet potatoes were carried across the Pacific by Peruvian Indians before Europeans began to sail the world's oceans; however, an article by Muñoz-Rodriguez, et al. in Current Biology (2018) offers convincing DNA evidence that Heyerdahl's hypothesis is incorrect. The article disputes the longstanding mystery of how sweet potatoes showed up in Polynesia before the Europeans set foot in South America where the plant evolved. This latest study suggests it is more likely that seeds of the sweet potato floated across the Pacific Ocean on sea currents more than a 100,000 years ago--ruling out human transport. Other Ipomoea species, such as I. pes-caprae, have excellent drift seeds (see R in following image). In fact, I have found this species on beaches of the Galapagos Islands. According to S.L. Kochhar (Economic Botany: A Comprehensive Study 5th Edition, 2016): The seeds of sweet potato, "which have an almost impervious seed coat, germinate after immersion in seawater."

Muñoz-Rodriguez et al. 2018. "Reconciling Conflicting Phylogenies in the Origin of Sweet Potato and Dispersal to Polynesia" Current Biology 28: 1–11 (April 23, 2018). https://doi.org/10.1016/j.cub.2018.03.020

Oxalis species (Oxalidaceae) have always been special to me. Bermuda buttercup (O. pes-caprae) was the first plant I keyed out in my plant identification class (Botany 110) every spring at Palomar College. Each lab I gave the class several unknown plants to key out with their text (Jepson Flora of California), including helpful illustrations and/or photo images (see links below). I eventually placed all of this material on-line when I started my website Wayne's Word. Oxalis was perfect for beginning students because all the characteristics were easy to see and the plants keyed out perfectly. Flowering O. rubra was the first macro photo I ever took with my first SLR camera. During the COVID-19 pandemic social distancing of March-April... 2020 I discovered dwarf wood-sorrel (O. micrantha) along a trail just north of the Palomar Cactus & Succulent Garden. I never saw an Oxalis with flowers this small. This species is naturalized in the foothills of central California. The San Diego Natural History Museum herbarium has one reported location for this species in the City of San Diego. This may be a new naturalized South American wildflower for San Diego County.

There are four species of Oxalis on Owens Peak and the Palomar College campus: Three naturalized species from the Mediterranean, South Africa and South America; and one species native to California and Baja California. They are often called "sour grass" or "sour clover" due to the lemony taste of oxalic acid in their stems and leaves. Probably everyone remembers chewing on an Oxalis plant as a child.

As of 21 Oct 2020 I have found 2 species of Lemna (duckweed) in Abejo Pond, L. minuta and L. turionifera. To my great astonishment I also found one Wolffia plant mixed with a large clump of duckweeds. It appears to be the Asian species W. globosa that I have found in Florida and occasionally in California (including San Diego County).