Summary:
Also listed in Veined category. Features include 1) bright orange to reddish color and smoothly pimpled surface, 2) growth on distorted Russula brevipes (and other Russula and Lactarius spp.) whose gills are often reduced to blunt ridges, 3) the anamorph not being found in nature, and 4) spores measuring 30-50 x 4.5-8 microns, 2-celled, warted, and apiculate. |The anamorph is not found in nature, (Poldmaa). |The edibility [of firm specimens] is often rated highly, although there is no absolute assurance that the host species is edible, (Arora). Although it is reportedly edible, some experience intestinal upset: it is probably best avoided since the host fungus cannot be identified accurately, (McKnight). |Researchers found that H. lactifluorum DNA "is not restricted to the margin but is distributed relatively evenly across the sporocarp of the lobster mushroom", and significant chemical changes occur as a result of the parasitization process, (Laperriere(1)).

Microscopic:
SPORES 30-50 x 4.5-8 microns, "spindle-shaped or shaped like caraway seeds", colorless, warted, 1-septate, (Arora). |SPORES 35-40 x 4.5-7 microns, fusiform, prominently verrucose and apiculate (verrucae 1-1.5 micron high, apiculi 4.5-7.5 microns long, acute, straight or curved), 2-celled, septum median; ASCUS 200-260 x 5-10 microns, long cylindric, "apex thickened and with a pore"; PERITHECIUM 400-600 x 200-450 microns, immersed except for papilla, KOH+, "papilla averaging 120 microns high, 120 microns wide", perithecial wall 25-30 microns wide laterally, cells 7-15 microns long, about 5 microns wide, fusoid, walls 1.5 micron thick, nonpigmented, perithecial apex composed "of circular to elliptic cells tending to be arranged in files and with long axis parallel to long axis of perithecium", 5-15 x 3-7 microns, walls 1.5 micron thick, cells around the ostiolar opening 3-5 microns wide, clavate, ostiolar canal periphysate; subicular hyphae "3-5 microns wide, septate, much branched, branching very irregular, often at right angles, densely compacted but remaining filamentous, smooth", occasionally some cells swollen to 10 microns wide, KOH+ purple, (Rogerson). |SPORES 35-45 x 5-8 microns, "fusiform, with one side sometimes flattened", verrucose ("verrucae low and confluent with each other, 1-1.5 microns high"), ends apiculate (apiculi 4.5-7.5 5m long, with acute tips), 1-septate (septum median); ASCUS 200-260 x 6-10 microns, "with apex thickened, penetrated by a pore"; PERITHECIA "caespitose, immersed in the subiculum except the papilla", 400-600 x 250-450 microns, "KOH reaction with the whole perithecium turning purple, reaction in the perithecial wall usually much weaker (or sometimes lacking) than in the papilla", perithecial wall 25-30 microns wide, perithecial papillae 120-220 microns high, 120-200 microns wide at base, 80-120 5m wide at top, tip obtuse, "of pseudoparenchymatous texture, with cells in divergent files, becoming narrower toward the ostiolar canal and more rounded towards the outer surface", cells at the surface 6-13 microns in diameter; subicular hyphae 3.5-8 microns wide, loosely interwoven to densely compacted, cells not swollen or occasionally swollen; anamorph in nature not observed; thick-walled cells absent, (Poldmaa)

Notes:
Hypomyces lactifluorum is found throughout North America (Phillips). Distribution includes NS, MB, and the majority of states in all 6 regions of US, including specifically IA, MI, NC, and PA, as well as Mexico and Guatemala, (Poldmaa). It is known only from North America: WA, OR, ID, MB, NB, NS, ON, PE, PQ, AL, AZ, CO, CT, DE, FL, GA, IA, IL, IN, KS, KY, MA, MD, ME, MI, MO, MS, NC, ND, NH, NJ, NM, NY, OH, PA, RI, SC, TN, TX, VA, VT, WI, WV, Guatemala, and Mexico, (Rogerson). It is reported from BC (Redhead(5) and there are BC collections at the University of British Columbia). There are AK collections at the University of Washington. Desjardin(6) shows it for CA.

Synonyms and Alternate Names:
Boletus piperatoides A.H. Sm. and Thiers
Geopora harknessii E. Fisch. ex Gilkey
Geopora magnifica Gilkey