## 4 Materials and Methods
### Floral Scent Collection and VOCs Identification  
We characterized the chemical composition of flower scent in eight focal _Jaborosa_ species (Table S3) that encompass the three pollination modes present in the genus: _J. integrifolia_, _J. odonelliana_ and _J. runcinata_ by nocturnal hawkmoths (Sphingidae); _J. leucotricha_, _J. lacinita_, _J. sativa_ and _J. rotacea_ by saprophilous flies (Anthomyiidae, Calliphoridae, Muscidae, Sarcophagidae); and _J. reflexa_ with generalized pollination by small insects (Syrphidae, Sarcophagidae and Halictidae). With the methods available to us (detailed below), we failed to detect any floral VOCs in two additional _Jaborosa_ species: _Jaborosa bergii_ Hieron. with a faint floral scent (unknown pollinators) and _J. magellanica_ with a full floral scent (sapprophilous fly-pollinated). Floral volatiles were sampled opportunistically from natural populations in Argentina from 2008 to 2014 and were analyzed by gas chromatography-mass spectrometry (GC-MS) using three different but complementary methods: dynamic headspace described with solvent, solid-phase extraction (SPE) microtraps combined with thermal desorption and solid-phase micro extraction fibers (SPME). Initially (2008-2010), we used dynamic headspace methods (see [13]) to collect scent from natural populations. We placed 4 L nylon resin oven bags (Reynolds Consumer Products, Inc., Lake Forest, IL, USA) over intact, blooming plants in the field to concentrate volatiles, then collected headspace air over glass Pasteur pipette traps with 10 mg of Porapak Q adsorbent (packed between plugs of silanized quartz wool) for 1 h, using 9V battery-operated PAS-5000 vacuum pumps (Spectrex, Inc., Redwood City, CA, USA) at a flow rate of 200 mL air/min. Trapped volatiles were eluted with 300 uL of GC-MS purity methylene chloride (2008) or hexane (2009-2010) (Sigma-Aldrich, Inc., St. Louis, MO, USA), concentrated to 75 uL (2008) or 50 uL (2009-2010) with a flow of gaseous N2, and 1 uL of each sample was injected in the GC-MS. A toluene dilution (5 uL of 0.03% toluene in hexane) was added to the concentrated samples as an internal standard [131]. Consistent with previous studies using similar methods [22; 131], samples from hawkmoth-pollinated _Jaborosa_ species produced chemical results that matched our olfactory perception (i.e., in emission rates and identified VOCs as character-bearing notes; see [65]). However, samples collected from taxa that we perceived as faint or foul scented yielded blank chromatograms using the dynamic headspace method. Thus, in subsequent years (2011-2014) we employed another method, direct (solvent free) thermal desorption coupled with GC-MS, to characterize floral scent composition mostly from the Andean clade species. We constructed solid-phase extraction (SPE) micrographs that are loaded directly into a modified GC injection port liner for thermal desorption, by filling small cut glass capillaries (15 mm long, 0.2 mm internal diameter) either with 5 mg Tenax TA (60/80 mesh; for [PERSON]. [PERSON]) or with a blend of 1.5 mg Tenax TA (60/80 mesh) and 1.5 mg Carbotrap B (for [PERSON]. [PERSON]) between plugs of silanized quartz wool (see [132]). Living flowers or entire plants were enclosed within bags constructed from sealed oven bag material (nylon resin; Reynolds, Inc.)) using an impulse heat sealer. The size of the headspace chambers varied according to the size and architecture of the flowers for each species (which vary greatly within the genus), always with the goal of minimizing headspace air volume [133]. When climatic conditions were harsh (e.g., high wind and frozen temperatures in the Andes), flowers of _J. laciniata_ and _J. leucotricha_ were cut and placed inside oven-clean glass vials (10-20 mL). Headspace air was allowed to equilibrate for 1 h, and volatiles were collected for 5 min (occasionally for longer times) using 9V battery-operated vacuum pumps (Spectrex, Inc.) set to 200 mL air/min flow rates.