Moeroris abnormis (Baill.) R.W. Bouman, Phytotaxa

Moeroris abnormis (Baill.) R.W. Bouman, Phytotaxa 540(1):30. 2022. BASIONYM: Phyllanthus abnormis Baill., Recueil Observ. Bot. View in CoL 1:42. 1860. Diasperus abnormis (Baill.) Kuntze, Revis.Gen. Pl. View in CoL 2:598. 1891. TYPE: U.S.A. TEXAS: 1835, Drummond 336 (HOLOTYPE: G G00434968!; ISOTYPES: GH GH00048515, internet image!, K K001056954, internet image!, P P04854497!, P04854498!).

Phyllanthus drummondii Small, Fl. S.E. U.S. 692.1333.1903. TYPE: U.S.A. TEXAS: Drummond III , 336 (HOLOTYPE: NY NY273011 , internet image!, NY273012 ,internet image!, one specimen over two sheets).

In the protologue for Phyllanthus abnormis, Baillon explicitly cited the specimen as being in “herb. Less.,” meaning the Delessert herbarium, which is now at G. The sheet P04854498 bears a packet containing a few fragments and labeled “ex herb. Lessertian.,” confirming the source. Therefore, the holotype is the specimen at G, and the other specimens cited above are isotypes.

Small, in the protologue for Phyllanthus drummondii , cited the specimen of Drummond 336 then at Columbia University, now at NY.At NY there are two sheets, explicitly labeled sheets 1 and 2. One is undated, but the other is labeled “v. Charp. 1839.” Because Drummond died in 1835, “1839” cannot be the collection date;presumably is the date it was received from elsewhere.If that is correct, the other specimens of Drummond 336 cited above are isotypes of P.drummondii and the specimen at NY is an isotype of P.abnormis .

Two varieties have previously been accepted within this species. The nominate variety has been treated as disjunct between peninsular Florida (now also known from Camden County, Georgia) and Texas, southwestern Oklahoma, southeastern New Mexico, and northern Tamaulipas, Mexico. The other variety, Phyllanthus abnormis Baill. var. riograndensis G.L. Webster , is restricted to the Rio Grande Valley in southern Texas ( Webster 1967, 1970; Levin 2016); although its geographic range of this falls within that of var. abnormis , they occupy different habitats and do not appear to co-occur (Levin, pers. obs.). They consistently differ in shape of the glands in the staminate flowers and the maximum number of staminate flowers in the bisexual cymules. Where they approach each other geographically, they also differ in that var. abnormis has smooth stems and var. riograndensis has scabridulous stems; elsewhere in the northwestern part of its range (not Florida, Georgia, or Tamaulipas), var. abnormis often has scabridulous stems ( Levin 2016). Webster (1970) stated that var. abnormis and var. riograndensis differ in seed length, but examination of more specimens shows this is not the case (Levin, pers. obs.).

Although both Webster (1967, 1970) and ( Levin 2016) noted that the Florida populations of var. abnormis (sometimes treated as Phyllanthus garberi Small ) have three stamens in one of the two staminate flowers in the proximal cymules, whereas both flowers have only two stamens in the western part of its range, and that the Florida plants have consistently smooth stems, unlike the often scabridulous stems found farther west, they chose not to recognize the Florida populations as a distinct taxon. Upon further reflection, we consider that these differences warrant taxonomic recognition. We also note that whereas the western plants are found on sandy prairies, barrens, and usually interior, often stabilized, dunes, the Florida and Georgia plants are found only on unstable, coastal dunes ( Webster 1970).

The differences in morphology and habitat combined with their disjunct distribution prompt us to recognize the Florida and Georgia plants at the subspecific rank. Although the lack of geographic disjunction between western var. abnormis and var. riograndensis might argue for retaining varietal status, the morphological differences between them are greater than those between the western and eastern forms previously included in var. abnormis ; treating them at a lower rank than the Florida/ Georgia taxon would not reflect morphological patterns. To reflect this fact and their parapatric distribution, we elevate var. riograndensis to subspecific rank.