FIGURES 192- 196
Subtribe BAERIINAE Benth. & Hook., Gen. PI., 2:200, 1873.
Subtribe ERIOPHYLLINAE Rydb., N. Amer. F1.. 34(2):81, 1915.
*
Amblyopappus Hook. & A m . (including Aromia Nutt., Infantea Remy in Gay), *Antheropeas Rydb.,*
Baeriopsis Howell,*
Eatonella A. Gray,*
Eriophyl- lum Lag., *Lasthenia Cass (including Baeria Fisch.& Mey., Burrielia DC., Crockeria Greene ex A.
Gray, Dichaeta Nutt., H o l o g m n e Bartl., Ptilomeris Nutt., Rancagua Poepp. & Endl., Xantho Remy),
*Lembertia Greene, *Monolopia DC., *Oxypappus Benth., *Pseudobahia (A. Gray) Rydb.
Annual or perennial herbs; leaves opposite or sometimes alternate, crowded on short stems in Baeriopsis; petioles lacking or indistinct. Inflores- cence terminal, with heads solitary on erect pe- duncles, laxly cymose, or in subcorymbose clus- ters. Heads usually heterogamous, sometimes dis- coid; campanulate to cylindrical: involucral bracts herbaceous, in ca. 2 series, ovate to orbi- cular, narrow in Oxypappus; paleae lacking. Ray flowers when present female; corolla limb papil- lose on upper surface, weakly to strongly trilobed at tip. Disk flowers hermaphroditic; corollas usu- ally 5-lobed; inner surface of lobes papillose, outer surface often with few to many short, flattened,
82 SMITHSONIAN CONTRIBUTIONS TO BOTANY
biseriate, nonglandular hairs, glabrous in Oxypap- p u s ; anther thecae pale; endothecial cells short, usually with 2-5 thickenings on transverse walls (with radial thickenings in Lasthenia; cells elon- gate with thickenings on lateral walls in Oxyfap- p u s ) ; anther appendages with or without glands.
Style branches with paired stigmatic lines, tips subtruncate or shortly apiculate. Ducts without colored resin; ducts of style shaft apparently out- side of veins, veins of style branches near outer surface and ducts possibly absent, ducts appar- ently present inside of veins in branches and upper shaft of Oxypappus style. Achenes prismatic to compressed, walls carbonized, with striations, usually with additional knoblike thickenings, with a smooth layer of carbonization in some species of Lasthenia; cells of seed coat not orna- mented; pappus of awns or squamellae or lacking, awns and squamellae without sharply demar- cated costal region. Pollen mostly 25-30 pm in diameter.
Members of the subtribe are concentrated in the western United States and northern Mexico.
One species, Amblyopappus pusillus Hook. & Am., has a disjunct distribution extending to Peru and Chile in South America.
Within the related series of epaleaceous sub- tribes, the Baeriinae differ by the lack of distinct petioles on the leaves, by the carbonized achenes with distinct striations, and by the usually short endothecial cells with 2-5 thickenings on the transverse walls. T h e short clavate hairs on the disk corolla lobes of a number of the genera always seem to be biseriate rather than mono- seriate as in some of the other subtribes in the series. Most genera of the Baeriinae are further distinguished from the related Peritylinae by the broader involucral bracts.
Oxypappus is evidently related to this subtribe by the form of the leaves and the achenes. How- ever, the genus has a number of anomalous fea- tures: an involucre with narrow bracts of the Perityle-type, elongate endothecial cells with thick- enings on the vertical walls, and resin ducts of the style inside the veins in the upper part of the shaft.
Various members of the subtribe that have been examined show weakly to strongly devel- oped conical receptacles. Also, a number of mem- bers, including Eatonella, Monolopia, and parts of Lasthenia, have compressed achenes. The achene of Monolopia is of particular interest. The shape of the carpopodium indicates that the achene ordi- narily lies against the conical receptacle in a tangential position, but the veins of the style are continuous with the edges of the achene, rather than with the flattened surfaces, showing that the achene is anatomically compressed rather than obcompressed.
The genus Lasthenia is here considered a natural genus which can be distinguished anatomically from others of the subtribe by the more radial pattern of thickenings on the endothecial cells.
T h e genus is also of interest chemically. It is one of the two elements in the Heliantheae that has long been known to contain anthochlor pigments (Bohm et al., 1974), and Bohm (1977) mentions that Lasthenia, on the basis of five species in two sections, differs from other “Helenieae” by having polyacetylenes based on the ene-tetrayne-ene se- ries rather than the pentaynene series. T h e mono- thiophenes in Lasthenia of the ene-tetrayne-ene series are particularly notable. It seems to be coincidence that both types of chemicals, the anthochlors and the ene-tetrayne-ene thiophenes, are most prominent elsewhere in the tribe in the subtribe Coreopsidinae. Contrary to the sugges- tion of Harcombe (1977), there is no other reason to associate Lasthenia with the Coreopsidinae.
Previously unnoticed in Lasthenia is the internal structure of the achene wall, which varies between two types. Lasthenia chrysostoma (Fisch. & Mey.) Greene, L. coronaria (Nutt.) Ornduff, L. leptalea (A.
Gray) Ornduff, L. minor (DC.) Ornduff, and L.
plaQcarpha (A. Gray) Greene have walls with evenly deposited phytomelanin interrupted only by micropunctations and striations. Lasthenia chry- santha (Greene ex A. Gray) Greene, L. glaberrima DC., L. glabrata Lindl., and L. microglossa (DC.) Greene have the phytomelanin more irregular and granular, with a n additional pattern of knob- like thickenings. T h e wall type in the first series
NUMBER 5 1 83
FIGURES 192-200.-Baeriinae-Chaenactidinae: 192, 193, Baertopsis quadalupensu J. T. Howell.
disk flowers with achenes, X 12; 194, Lasthenta chrysostoma (Fisch. & Mey.) Greene, disk achene.
X 17; 195. Oxypappus seemannii (Sch.-Bip.) Blake, disk achene. X 17: 196, Eatonella congdonii A.
Gray, achene, X 12; 197, Espejoa mexicana DC., achene, X 8: 198, Palafoxta sphacelata (Kutt. ex Torr.) Cory, d i s k achene, X 8; 199, Bahia absinthtfolta Benth., d i s k achene with corolla. X 12:
200, Hypertcophy llum multicaule Hutchins., achene, X 6.
84 S M I T H S O S I A N C O N T R I B U T I O N S TO B O T A N Y
is the same as that seen without striations in the typical members of the subtribe Peritylinae. Ex- amination of a series of L. microglossa indicates the character is stable within a species. Attempts to correlate with the groups of Ornduff (1966) show the first type of wall in sections Baeria, Platycarpha, Ptilomeris, and one species of Burrielia. T h e second wall type is in sections Hologymne, Lasthenia, and another species of Burrielia. Only in section Bur- rielia has hybridization been reported by Ornduff between species shown here to have different wall types, and those hybrids were sterile.
T h e variation in the achene wall in Lasthenia can be compared also with the results of the detailed study of the flavonoid pigments in the genus (Bohm et al., 1974). T h e first type of achene wall, the Perityle-type, is found in groups with the most highly developed anthochlor chemistry as well as those with the nonanthochlor flavonoid patuletin. T h e second wall type is found in species which have less complex anthochlors or species with no specialized flavonoids. In the flavonoid study, the species with anthochlors are regarded as primitive within the genus, and the species without anthochlors are considered derived. As such, the Perityle-type of achene wall would also be primitive within the genus. It is notable that neither the Ornduff sections, the flavonoid types, nor the achene wall types correlate completely. It is notable, also, that anthochlors and Perityle-type achene walls are not found in the other genera of the Baeriinae, and they almost certainly are not primitive in the subtribe. Just as the anthochlors do not seem to reflect close relation to the Cor- eopsidinae, the evenly deposited phytomelanin of the achene wall does not seem to reflect a direct relationship of Lasthenia to Perityle.