Hedyotis angulata Fosberg ex Shinners


Family: Rubiaceae

Synonyms: Hedyotis nigricans (Lam.) Fosberg var. angulata (Fosberg ex Shinners) W.H. Lewis; Hedyotis nigricans (Lam.) Fosberg var. parviflora (Gray) W.H. Lewis; Hedyotis stenophylla Torr. & Gray var. parviflora Gray; Houstonia rupicola Greenm.

Remarks: About six years ago, Guy Nesom told Rich Spellenberg (who alerted me) that Hedyotis angulata occurred in New Mexico. Now I am unable to verify this species for the state. I have been corresponding with Tom Wendt (TEX Curator) and Guy Nesom and received the following information from them.

Tom could not find a TEX specimen of H. angulata from New Mexico. He points out that the Hedyotis collection at TEX has been recently studied and annotated by Billy Turner and his findings published in a series of Phytologia articles. Turner mentions and maps H. angulata in one of these papers (Turner 1995) because it superficially resembles Hedyotis nigricans - which is the topic of the paper.

Turner places H. angulata in the Big Bend counties of Pecos, Crockett and Val Verde, Texas and in adjacent Coahuilla, Mexico. He shows Hedyotis nigricans var. papillacea in north and Trans-Pecos Texas. Tom says there are two specimens of the latter from the Guadalupe Mountains on the NM side of the border. He suspects that these may have been the source of the rumor that H. angulata occurred in New Mexico.

Guy said "I don't remember the exact conversation with Rich S. but it does sound like I was looking at those two papillacea and calling them Hedyotis angulata. My concept of the taxa at that time clearly wasn't very sophisticated."

Tom holds out the other possibility that the circumscriptions of H. angulata and H. nigricans var. papillacea may vary between Turner and Ed Terrell (Univ of Maryland) and that Terrell might perhaps call the Guadalupe Mountain plants H. angulata. Anyone reading Phytologia lately can see that these two authorities differ widely (and forcefully) in their opinions concerning Hedyotis.

I could contact Terrell for his opinion, but don't feel like this would serve the NMRPTC purposes. If the Trans-Pecos populations are H. angulata, then it is not a very rare plant. For now, I think we should drop Hedyotis angulata from the rare plant list and from the Working Index of New Mexico Plant Names.

Important Literature:

Turner, B.L. 1995. Taxonomic overview of Hedyotis nigricans (Rubiaceae) and closely allied taxa. Phytologia 79(1):12-21.

Information Compiled By: Bob Sivinski